Browse Topic: Conductivity

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Tailored Thermo-Mechanical Behaviour of CNT/Epoxy Nanocomposites via Solvent-Assisted Dispersion2026-99-01897/31/2026
Carbon nanotube (CNT) reinforced epoxy nanocomposites were prepared using a solvent-assisted dispersion method and characterized to evaluate their structural, mechanical, and thermal behaviour. X-ray diffraction (XRD) confirmed the presence of CNTs in the polymer matrix through the characteristic (002) reflection, while scanning electron microscopy (SEM) revealed that CNTs were found to be uniformly embedded within the epoxy matrix, showing limited agglomeration and strong interfacial bonding. Fourier-transform infrared spectroscopy (FTIR) supported these observations by revealing absorption bands associated with C=C stretching, C–O–C ether linkages, and O–H vibrations, indicating chemical interactions between CNTs and the epoxy network. Mechanical testing showed that CNT concentrations of 0.25–0.50 wt.% provided the most effective reinforcement, with notable and measurable improvements in tensile and compressive strength as well as modulus. At higher CNT loadings, however, agglomeration led to reduced tensile performance, despite compressive strength remaining comparatively stable. Thermal conductivity increased steadily with CNT addition, from 0.2143 W/m.K for neat epoxy to 0.2435 W/m.K at 0.75–1.00 wt.%, with the most pronounced improvements observed above 0.25 wt.% due to the formation of more efficient conductive pathways. Overall, these findings suggest that low-to-intermediate CNT loadings achieve a practical and useful balance between strength and thermal conductivity while avoiding the drawbacks of excessive filler content. Effective dispersion of nanotubes is a critical factor that governs the mechanical and thermal behaviour of the composites. These results indicate that CNT/epoxy nanocomposites produced under optimized conditions can serve as lightweight, mechanically reliable, and thermally stable materials, making them attractive candidates for advanced applications in aerospace, automotive, and energy-related sectors where both structural performance and efficient thermal management are required.
Gul, Aysenur, Kamali, Ali Reza
Research on the Influence of Creping Process and Microstructure on the Properties of Crepe Paper Products2026-99-02067/31/2026
Crepe paper has extensive applications in the electrical field and significantly influences the operation of power equipment. The creping process and microstructure play a crucial role in determining its performance. However, optimizing them to improve the performance of crepe paper remains a challenge. Therefore, in this study, univariate and multi - factor interaction experiments were set up to explore the impact of the creping process on crepe paper. X - ray diffraction (XRD) and Fourier - transform infrared spectroscopy (FTIR) techniques were used to analyze the microstructure of crepe paper. The results show that smaller scraper angles and moderate pressures can increase the paper density, and the use of different creping aids can improve the paper’s performance. Higher crystallinity enables crepe paper to have better mechanical and thermal stability. Moreover, based on the experimental results, a scheme for optimizing process parameters was proposed to help improve the quality of domestic crepe paper and provide support for the development of domestic electrical crepe paper production technology.
Meng, Gao, Ran, Zhuo, Yuan, La, Zengchao, Wang, Bin, Zhang
Characterization of Dynamic Characteristics of Pneumatic Systems Based on Aerodynamic Frequency Ratio2026-99-02307/31/2026
To address the ambiguity in the relationship between design parameters and energy characteristics in pneumatic systems caused by gas compressibility and low viscosity, which leads to design redundancy, this paper proposes a dynamic characteristic characterisation method based on the pneumatic frequency ratio. This aims to establish a correlation mechanism between system energy consumption and dynamic performance. By constructing a nonlinear dynamic model of a double-acting cylinder, the dimensionless aerodynamic frequency ratio (Ω) is defined to characterise the matching relationship between the system’s natural and operating frequencies. Analytical relationships between Ω and key design parameters—such as cylinder diameter and valve sound velocity conductance—are derived, thereby establishing a normalised similarity criterion. Through combined simulation analysis and experimental validation, the regulatory patterns of Ω on the dynamic characteristics of displacement, velocity, and pressure are systematically investigated. Results indicate that under consistent Ω conditions, the normalised dynamic characteristic error across aerodynamic systems with varying parameters can be controlled within 4%. A significant linear correlation exists between the frequency ratio and the amplitude of cylinder chamber pressure differentials, with errors below 3%. The study further reveals that Ω exerts a nonlinear regulatory effect on system responsiveness and stability: increasing Ω enhances dynamic response speed but exacerbates pressure fluctuations, whereas decreasing Ω slows response but improves pressure stability. This methodology provides a theoretical foundation for energy-efficient design, parameter matching, and intelligent control of pneumatic systems, effectively addressing a gap in existing research on energy-dynamics coupling analysis.
Li, Mengru, Du, Hongwang, Wang, Jiajia, Yuan, Tingting, Xiong, Wei
Energy-saving and Economic Evaluation of Vacuum Insulation Panels with Glass Wool Core-polyimide Membrane Structure in Hotel Buildings under Different Climatic Conditions2026-99-16527/24/2026
This study prepares high-performance PI/VIP composite thermal insulation materials for buildings by integrating polyimide (PI) composite membranes and vacuum insulation panels (VIPs), and uses EnergyPlus to explore their impacts on building energy conservation, operating costs, and carbon emissions under different climates. Experimental results show the materials have low thermal conductivity, long service life, and excellent thermal insulation and flame-retardant properties due to their internal vacuum structure inhibiting heat transfer. Simulations in Jinan (tropical monsoon), Heilongjiang (cold temperate), and Shenzhen (subtropical humid) climates indicate that compared with traditional XPS and rock wool boards, buildings using PI/VIP composites achieve 21.3%, 34.7%, and 18.9% higher annual energy-saving efficiency respectively, with 27%-41% lower carbon emissions; the most significant effects in Heilongjiang highlight the material’s great promotion potential in severe cold areas.
Bian, Chenqian, Chen, Zhaofeng
Evaluation of Thermal Behaviour of Ramie Fiber/Delrin Composites for Aircraft Cabin Components2026-26-07546/1/2026
This research investigates the fabrication and evaluation of Delrin (polyoxymethylene, POM) composites reinforcing 5-20 wt.% chopped ramie fiber (RF). The polymer composites were fabricated via the injection moulding technique. Glass transition temperature (Tg), thermal conductivity, Vicat softening temperature (VST), heat deflection temperature (HDT), melt flow index (MFI), and coefficient of linear thermal expansion (CLTE) were the various thermal characteristics of the sustainable composites that were systematically evaluated as per the ASTM standards. The addition of RF drastically altered the Delrin matrix's performance. Among the formulations, the composite with 15 wt.% RF had the best combination of properties: higher VST and HDT values, which provide greater dimensional stability at high temperatures; lower CLTE, resulting in less thermal expansion; comparatively better thermal conductivity; and improved heat dissipation. Eventually, there was a moderate drop in the MFI, indicating more rigid polymer chains that restrict the flowability of the composite, thereby increasing its heat-withstanding capabilities. DSC analysis revealed a slight upward shift in Tg and increased crystallinity, suggesting restricted polymer chain mobility and enhanced load transfer at 20 wt.% RF loadings, agglomeration effects, and weaker interfacial bonding with the matrix led to deterioration in properties. Aircraft cabin components like interior panels, ducting supports, and lightweight non-structural fittings requires dimensional stability, thermal resistance, and mechanical reliability under fluctuating flight conditions.
S, Thirumalvalavan, Senthilkumar, N., Selvarasu, S
Copper-Beryllium Alloy (Copper Alloy Numbers C17500 and C17510), StripAS81021B (Historical)5/20/2026
This specification covers the requirements for the acquisition of two alloys of copper-beryllium alloy strip, having higher electrical conductivity than copper-beryllium alloy strip normally used (see 6.1). All sizes of strip are covered by this specification.
AMS D Nonferrous Alloys Committee
Hardness and Conductivity Inspection of Wrought Aluminum Alloy PartsAMS2658E (Current)5/6/2026
This specification establishes hardness and electrical conductivity acceptance criteria for finished or semifinished parts made from wrought aluminum alloys after heat treatment (see 8.6).
AMS D Nonferrous Alloys Committee
Role of Advanced Polishing Techniques in Enhancing Al-Cu Diffusion Bonding for EV Application2026-01-02354/7/2026
The demand for lightweight, high-efficiency components in electric vehicles (EVs) highlights the critical need for reliable Al-Cu joints with superior electrical and thermal conductivity. While diffusion bonding has emerged as a promising approach, interfacial impurities and voids often degrade joint quality and conductivity. Conventional manual polishing was initially employed to prepare Cu and Al surfaces; however, this method proved insufficient in consistently removing oxides and contaminants, leading to non-uniform bonding. In addition, the larger surface area of the samples made traditional polishing impractical, further motivating the use of electropolishing. To overcome these limitations, we introduce electropolishing pretreatment to achieve cleaner, void-free interfaces. Electropolishing effectively dissolves surface asperities and contaminants, enabling intimate atomic contact during bonding and minimizing the formation of brittle intermetallic phases. A systematic investigation of bonding parameters was conducted using a custom-designed graphite clamping system. Microstructural analyses reveal that advanced polishing plays a pivotal role in producing uniform, impurity-free interfaces, resulting in reduced intermetallic thickness, improved bonding strength, and enhanced current-carrying capability. This study demonstrates the clear advantages of electropolishing over conventional polishing and establishes a scalable pathway to manufacture high-performance conductive joints for next-generation EV motor and power distribution systems.
Abbasi, Hossein, Liu, Yi, xiao, Yaohong, Wang, Andy, Su, Jinrong, Wang, Qigui, Chen, Lei
Application of DFSS for Optimizing Thermal Protection in Electric Vehicles during Battery Thermal Runaway Events2026-01-01424/7/2026
Battery thermal runaway is a major safety concern in electric vehicles because of the extreme heat and hazardous gases released during cell failure. These venting events can quickly raise the temperature of the battery enclosure and cabin floor, threatening occupant safety. To address this challenge, this study employs the Design for Six Sigma (DFSS) methodology to design and optimize a thermal protection system that delays and limits heat transfer to the cabin. A physics-based transient heat-transfer model was combined with DFSS principles to systematically evaluate insulation materials, shield layouts, surface emissivity, and layer geometry. An L-18 orthogonal array was used to identify key parameters and quantify their influence on thermal robustness. The optimized architecture reduced cabin-floor temperature rise under severe runaway conditions (600–900 °C vent gas), meeting occupant-egress safety requirements. Findings confirm DFSS as an effective framework for developing high-robustness EV thermal protection systems under uncertainty and extreme boundary conditions.
El-Sharkawy, Alaa, Asar, Mona, Taha, Nahla, Sheta, Mai
Experimental Study of Hydrogen Combustion in Argon-Oxygen Mixture Using an Optical Engine2026-01-03284/7/2026
The Argon Power Cycle (APC) is an emerging high-efficiency combustion technology for internal combustion engines. In APC, the conventional air-based working fluid is replaced with an inert argon gas. This substitution inherently increases engine efficiency through thermodynamic properties of argon, in particular a high adiabatic factor ?? ~1.67. A hydrogen-fueled APC engine offers the potential for highly efficient zero emission combustion by also eliminating nitrogen oxide (NOx) formation. In the present paper, hydrogen combustion is studied in an optical heavy-duty research engine, with the objective of providing the first visualization of H2 combustion in an argon–oxygen mixture. A comparative analysis of high-speed optical imaging and in-cylinder pressure measurements is conducted for two different modes: 1) conventional air operation and 2) argon-oxygen mixture operation. The high-speed images reveal a distinctly different combustion process between the two operating modes. The main results of the study are as follows: 1) The cylinder peak temperature during compression, estimated from cylinder pressure, increases from approximately 800K (air) to 1200K (argon-oxygen). 2) Abrupt hydrogen pre-ignition was observed for the argon-oxygen mixture, leading to strong pressure oscillations. In contrast, for hydrogen-air combustion, the mixture was ignited by the spark without pre-ignition. 3) The initial heat release was significantly higher in the argon-oxygen mixture yielding a pressure rise in a few crank angle degrees (CAD) in contrast to 5-10 CAD for the air mixtures. 4) Extremely lean hydrogen combustion was observed for the argon-oxygen case.
Kapp, Joakim, Cheng, Qiang, Kaario, Ossi, Vuorinen, Ville
Adhesion Strength of Coatings in Battery Structural Joints2026-01-02384/7/2026
In the design of Rechargeable Energy Storage System (RESS) structures, including battery trays, module side plates, and end plates, there are multiple conflating factors, including: Mechanical requirements necessitating the use of electrically conductive materials (steel and aluminum); proximity between battery module structure and battery cells, necessitating the use of electrical isolation coatings; and, module and pack designs that retain cells via the use of Structural Adhesive Material (SAM). Inherently, with this design approach, organic coatings are placed in a new and perilous position. In a sense, the coating becomes a supplement to an adhesive. As Computer-Aided Engineering (CAE) virtual analysis tools become more sophisticated, there is increasing reliance on these tools to predict the occurrence of structural failures in various load cases. Factors in test method, paint pretreatment, and topcoat affecting adhesion of organic coatings in structural adhesive joints are discussed, including: Adhesive sample preparation; adhesive selection, coating film pretreatment; age of pretreatment bath; acid cleaning; substrate material type (steel vs. aluminum); substrate product form effects within aluminum, and coating thickness. This information is useful for organic coating process development on metallic substrates. It is especially useful for material constructions requiring paint in contact with structural adhesives, as in these joints, paint adhesion is often a limiting factor on the performance of the structural adhesive. The characterization and optimization of this interface is especially important for EV battery modules & packs.
Moceri, Charles, Harper, Jared
Thermal Finite Element Modelling and Prediction of Laser Welded Battery Packs2026-01-03854/7/2026
Battery modules consist of battery cells electrically joined at the terminals by conductive busbars. Laser welds are the most consistent and controllable process to create these connections on a large scale due to their control over power, laser width, speed, wobble, and overlap, and their quality is critical to battery pack performance. Tuning these parameters for an application typically requires weld trials to reach desired weld width, penetration, and strength without overheating the battery cell and weakening the dielectric insulators around the terminals. Poorly welded cells in a module can result in increased electrical resistance, causing greater joule heating and accelerated cell aging, and poorly welded modules can lead to uneven aging and unpredictable performance. To better understand the laser welding process, a modelling approach was developed to predict weld properties to reduce production time, costs, and potential cell damage. The 3D finite element model was calibrated using test data gathered using 1 mm thick aluminum busbars being welded onto 25 mm aluminum terminals with varying laser parameters. A volumetric gaussian heat source was used to characterize the modelled laser. Melting and vaporization in the weld were captured without explicitly modelling them by adjusting the model’s material properties to improve computational efficiency. Each simulation’s predicted melt pool cross section was compared to that of each corresponding weld trial. This modeling approach led to the development of a parametric tool that could quickly predict laser melt pool width and depth which can be used to accelerate laser weld process development.
Contreras, Luis, Hoffmeyer, Matthew, Abidin, Zainal
Simplified Thermal Runaway Propagation Modeling to Design a Mass Optimized Battery Pack2026-01-04044/7/2026
This paper presents a simplified approach to model thermal runaway propagation in a multi-cell battery pack, with the goal of designing a safe and lightweight pack for mass-sensitive applications. The key parameters which characterize single-cell thermal runaway, including heat release profile, apparent cell emissivity and mass loss, were extracted from empirical nail penetration tests. This characterization was used to drive a three-dimensional thermal model of a 19-cell hexagonal sub-pack with a center trigger cell. To enable rapid design exploration, a symmetry-based computationally simplified domain was used for a full-factorial Design of Experiments (DOE) varying cell spacing, epoxy thickness, heat spreader thickness, and cup geometry. The DOE results were used to identify dominant heat-transfer mechanisms, capture main and interaction effects, and determine mass-efficient design levers governing peak-neighbor cell temperature during propagation. Insights from the DOE study informed the design of a physical prototype and the placement of thermocouples for model validation. Measured temperature data showed good agreement with model predictions across multiple initiator locations, with 4–7 °C error in peak temperature and 3–5 s error in time to reach peak temperature. However, accurate reproduction of the observed trends required increasing epoxy thermal conductivity on the initiator cell to represent epoxy carbonization observed during post-test teardown. This simplified modeling approach, paired with targeted testing, can provide practical design guidance, reduce overall testing cost, and enable fast development of mass-optimized, propagation-resistant battery packs.
Kalyankar, Apoorv, Owen, Elliot, Strohmaier, Kyle, Mardall, Joseph
Titanium Alloy Bars and Forging Stock, 6.0Al - 2.0Sn - 4.0Zr - 2.0Mo, Duplex AnnealedAMS6905D (Current)2/18/2026
This specification covers a titanium alloy in the form of bars up through 3.000 inches (76.20 mm), inclusive, in diameter or least distance between parallel sides with a maximum cross-sectional area of 10 square inches (64.5 cm2) and forging stock of any size (see 8.7).
AMS G Titanium and Refractory Metals Committee
Galvanic Corrosion Susceptibility Analysis and Mitigation Strategies in Automotive Battery Packs2026-28-00182/12/2026
As electric vehicles continue to revolutionize transportation, ensuring the reliability of their powertrain systems and Battery Packs has become a critical focus. One key challenge is galvanic corrosion, which occurs when dissimilar metals in contact are exposed to an electrolyte, such as seashore moisture or road salt used in snow or ice zones. This corrosion can weaken structural components, compromise electrical conductivity, and reduce the lifespan of critical systems. Common areas at risk include metallic joints within battery enclosures, busbars, cooling systems, and electrical connectors. Environmental factors such as high humidity and temperature fluctuations further amplify the issue, making it a pressing concern for manufacturers. This paper aims to systematically identify critical galvanic joints within electric powertrain systems and Battery Packs and provide effective strategies to mitigate corrosion risks. Preventative measures include choosing compatible materials with similar electrochemical properties, applying protective coatings, and utilizing dielectric barriers to isolate metals. Design optimizations, such as minimizing contact surfaces and improving drainage, can reduce the accumulation of electrolytes, while sealed enclosures and humidity management systems offer additional environmental protection. Regular maintenance and inspections are essential to detect early signs of corrosion and prevent long-term damage. By integrating these strategies into manufacturing and design workflows, automakers can enhance the durability, safety, and overall performance of electric powertrain systems ensuring they meet the growing demands of sustainable mobility.
Narain, Aditya, Venugopal, Sivakumar, Gopalan, Vijaysankar, Varatharajan, Senthilkumaran
State-of-the-Art Battery Thermal Management Technologies for SCV EV: An Integrated Approach to Enhance Energy Utilization and Reduce Expenses2026-26-00761/16/2026
The performance, lifespan, safety, and overall cost of high-voltage batteries—central elements in electric vehicles (EVs)—are fundamental to the success of the entire EV industry. These batteries, primarily used as energy storage systems, are especially critical in small commercial vehicles (SCVs), where efficient thermal management directly impacts reliability and durability. This paper presents innovative methods to improve energy efficiency, driving range, charging speed, and cost-effectiveness by combining advanced insulation techniques with thermoelectric cooling systems (TECs). The automotive industry is growing in EV domain and mostly in commercial vehicle application. The major challenge in EV’s is maintaining battery temperature to get optimal performance and best battery warranty. The key strategy of this research is providing insulating materials to stabilize battery temperatures. The thermal insulation minimizes thermal losses and buffers against external environmental conditions, reducing the cooling and heating system’s workload. This leads to lowering the operational demand on the compressor, pump and fan ultimately optimizing energy consumption. In this work, polyethylene terephthalate (PET), with a thermal conductivity of approximately 0.026 W/m-K, is used as the insulating material. In addition to thermal insulation, the integration of thermoelectric cooling systems provides precise temperature regulation by the thermoelectric effect to move heat away from battery cells either to TES tank or to ambient. In this setup, a thermal energy storage (TES) unit works alongside TECs as a cost effective thermal management solution for SCVs. Unlike traditional refrigeration systems, this approach replaces the refrigerant cycle with TEC modules and a PCM based TES tank. During the vehicle’s charging phase, TECs draw power externally to store cooling energy in the TES unit. Then, during operation, the stored energy maintains battery temperatures without consuming power from the high voltage battery. In colder climates, the same TEC modules can works as battery heater by reversing electric polarity. This paper is succeeding part of advanced battery thermal management technologies for SCVs: a comprehensive approach to optimize energy use, enhance battery performance and cost reduction, technical paper which is presented in TTTMS 2025. The optimization of existing thermo-electric system is important from system sizing, costing and performance point of view. In this paper the system is optimized and made compact with better thermal performance. In summary, combining advanced insulation and thermoelectric cooling strategies for non-air-conditioned SCV EVs results in significant benefits— including increased driving range and a 25–30% reduction in overall system costs—while still meeting stringent battery thermal management requirements.
Chormule, Suhas Rangrao, Warule, Prasad, Nagpure, Rahul, Jadhav, Vaibhav
Simulation Based Approach to Optimize Electric Vehicle Battery Thermal System2026-26-03761/16/2026
The performance and longevity of Li-ion batteries in electric vehicles are significantly influenced by the cell temperature. Hence, efficient thermal management techniques are essential for battery packs. Simulation based optimization approaches improves the efficiency of the battery pack thermal management during the early stage of product development. In this paper, a simulation-based methodology has been introduced to increase the heat transfer from/to coolant via cooling plate as well as to reduce the heat transfer from/to the external environment. The heat transfer coefficient between cooling plate and coolant needs to be enhanced to achieve efficient heat transfer through cooling plate, without exceeding the coolant pressure drop the target limit. A one-dimensional simulation methodology described in this work analyzed numerous design of experiments for coolant layout without performing CAD iteration loops and optimized the cooling channel width, height and number of channels to maximize the heat transfer coefficients within the pressure drop target. A reduction of 30% in pressure drop and 36% energy saving in coolant pump along with 10% enhancement in heat transfer effectiveness has been achieved with this method. This study also evaluated the sensitivity of each housing surface in heat transfer to external ambient. Simulation results provided recommendations for thermal insulation at minimum number of surfaces with thermal conductivity and thickness guidelines which gives maximum effectiveness at minimum material addition and cost. In the final part of this work, both the solutions have been integrated into the battery pack and compared with the baseline for energy consumption. A standstill parking condition at different low ambient conditions for different durations has been considered and energy consumption for pre-heater circuits has been evaluated. Results show that the energy consumption for pre-heater circuits was reduced by at least 31% to a maximum of 84% for the parking duration of 48 hours and 8 hours cases respectively. Thus, the simulation based integrated approach of two solutions helps to design energy efficient battery thermal systems during the design stage for Electric vehicles.
U, Reghunath, P S, Shebin
Optimizing Busbar Design by Investigating Critical Parameters and their Influence on Electrical and Thermal Behaviors for Reliable Electric Vehicle Battery Packs2026-26-04741/16/2026
With the rise of EVs, researchers are focusing on optimizing busbar design to meet the demands of high energy density, fast charging, and compact battery packs. The busbar design starts by selecting the material and the cross-sectional area required based on the rated current requirement. The width matches or may exceed the battery cell terminal size, whereas the length is optimized such that it is packaged within the given space constraints. The research also highlights the risk of busbars to oxidation and corrosion, which increases resistance and decreases conductivity for which plating/coating techniques are applied to improve the surface finish, overall durability, conductivity and in some cases the surface hardness, while minimizing the heat loss. Using simulations and experimental validation, the study examines three key design parameters: the weld diameter for busbar welded joints, electrical resistance, and contact resistance. A detailed analysis investigates how the weld diameter influences the electrical resistance and temperature rise over ambient and the impact of contact resistance between busbars and battery cell terminals on energy efficiency and thermal behavior. The above parameters if not designed and optimized may create a bottleneck in achieving a higher performance which the cells can deliver but it will be limited because of an uneven current distribution, higher heat generation and busbar temperatures exceeding the limiting values. This makes the busbars a critical component in the battery pack design for achieving the desired performance as well as reducing concerns of overall battery safety. This study highlights the importance of an optimized busbar design for creating safer, more efficient, and reliable EV battery packs by addressing key thermal and electrical challenges.
Nogdhe, Yogesh, Singh, Shobit Kumar, Paul, Jibin, Mishra, Mukesh, Menon, Praveen
Development of Advanced Thermoplastic Elastomeric Mat and Its Study on Thermal Performance of Wireless Charger System2026-26-02831/16/2026
This study aimed to develop a thermally conductive TPE mat and assess its performance in comparison to an existing antiskid rubber mat, specifically evaluating its impact on wireless charger efficiency. Moreover, morphological and thermal analyses were conducted to establish a correlation between the material behaviours of the new and current thermally conductive antiskid mats. The process of developing the thermally conductive TPE involved utilizing a two-roll mill followed by compression moulding to achieve a 2D sheet shape. Notably, the thermally conductive mat demonstrated a consistent enhancement in charging efficiency over the conventional antiskid mat. To examine the thermal characteristics, thermal characterization techniques including DSC and TGA were employed for both the existing and newly developed mats. FTIR spectroscopy was also utilized to confirm the presence of organic functional groups within the mat. The morphological analysis of the fillers used to enhance thermal conductivity was conducted through SEM. The resulting insights contributed to understanding the structural changes that contributed to the improved thermal performance. Subsequently, the developed thermally conductive mat sheet was evaluated in the context of wireless charger performance. The findings and implications of these evaluations were thoroughly discussed. In summary, this research successfully developed a thermally conductive TPE mat and highlighted its superior performance in terms of wireless charging efficiency compared to the traditional antiskid mat. Thermal and morphological analyses provided deeper insights into the material properties, while the evaluation of the mat's impact on wireless charger performance demonstrated its practical significance.
Naikwadi, Amol Tarachand, Mali, Manoj, Patil, Bhushan, Tata, Srikanth
Multifunctional ANF/Mxene-Enhanced Hydrogels for Flexible EMI Shielding and Wearable Sensing ApplicationsTBMG-544161/1/2026
Researchers from Harbin Institute of Technology and their collaborators have developed a multifunctional polyelectrolyte hydrogel reinforced with aramid nanofibers (ANFs) and MXene nanosheets, achieving outstanding performance in absorption-dominated electromagnetic interference (EMI) shielding and wearable sensing. This innovative hydrogel addresses the long-standing challenge of balancing electrical conductivity and effective EMI absorption in flexible electronic materials. The research was published in the journal Nano-Micro Letters. 1
Mixed Aggregation by Comprehensive Normalization Technique–Based Parametric Optimization of Turning of Ti-6Al-4V Alloy in Minimum Quantity Lubrication Environment05-19-03-002212/19/2025
Although Ti-6Al-4V alloy offers high strength-to-weight ratio, corrosion resistance, and biocompatibility properties, its machining is challenging due to low thermal conductivity, high hardness, and chemical reactivity. This study examines turning of Ti-6Al-4V under minimum quantity lubrication (soybean oil). Cutting speed (CS), feed rate (FR), and depth of cut (DOC) are considered as the input parameters. On the other hand, material removal rate (MRR), tool wear rate (TWR), surface roughness (SR), and cutting force (Fc) are treated as the responses. Optimization of the said process is carried out using the mixed aggregation by comprehensive normalization technique (MACONT), a recently developed multi-criteria decision-making (MCDM) method. The optimal parameters are identified as CS = 72.26 m/min, FR = 0.022 mm/rev, and DOC = 0.2 mm, achieving high MRR with low TWR, SR, and Fc. The effects of different turning parameters on the responses are also investigated. Sensitivity analysis confirms robustness, and comparative evaluation with other MCDM tools validates accuracy of the adopted approach. The results demonstrate MACONT’s effectiveness in optimizing turning of hard-to-machine alloys, supporting greener and sustainable machining practices.
Das, Partha Protim, Sharma, Saurabh, Chakraborty, Shankar
Synergistic Effects of Graphene Oxide and Nanoclay on the Structural and Electrical Properties of Automotive Nanocomposite Insulation2025-36-016112/18/2025
As vehicles become increasingly connected and electrified, the demand for high-performance cables and electrical connectors is growing quickly. Electrical insulation materials play an essential role in protecting and insulating those critical components, ensuring reliability, safety and durability. The development of a more robust composite material is essential to promote sustainability and energy efficiency, in both component application and its manufacturing processes. This research explores the development of advanced nanocomposite material for automotive electrical applications. The nanocomposite material comprises low-density polyethylene (LDPE), ethylene-vinyl acetate (EVA), nanoclay (NC) and graphene oxide (GO), processed via melt mixing in a twin-screw extruder. A design of experiments (DOE) was performed using 23, factorial design two levels and three variables (wt.% of EVA, NC and GO), to evaluate the effect of each variable on the material performance. Mechanical tests, (longitudinal stability, tensile strength and elongation at break), electrical insulation (dielectric strength and electrical resistivity) and flame-retardant properties were evaluated. The synergistic effect of GO and NC improved nanofiller dispersion and polymer-filler interactions, leading to enhanced structural integrity and efficiency for such applications. Experimental results confirm that the developed material offers improved resistance to deformation while maintaining excellent processability, that is critical for automotive wiring protection. An optimization of EVA, GO and NC was performed, and the nanocomposite material ensures enhanced insulation, mechanical strength and environmental resistance.
Horiuchi, Lucas Nao, Kerche, Eduardo Fischer, Gonçalves, Everaldo Carlos, Polkowski, Rodrigo
Development of Temperature Sensor for Automotive2025-28-039410/30/2025
The work presents a micro-electromechanical system (MEMS) temperature sensor that has been designed using COMSOL Multiphysics 6.0 software for use in predicting the temperature of automotive parts. Due to its versatility, the shape of this design employs a meander, and this involves joule heating physics. It clearly shows the variation of resistance with temperature. For this design, Nitinol nano material is used because of the following advantages: Enhanced Shape Memory Effect, Superior Super elasticity, Increased Surface Area, Increased Surface Area, Improved Biocompatibility, Tunable Properties, Enhanced Mechanical Properties. Nitinol having high strength to weight ratio find its application in aerospace industry. This sensor works based on the principle of temperature dependence of resistance; that is, the resistance of the material increases or decreases based on temperature. It is observed that Nitinol has low von Mises stress, proving the safety nature of the material in operating conservative stress regime
P, Geetha
Role of Charging Rate on Internal Short-Circuit Characteristics of Lithium-Ion Battery14-14-03-002010/7/2025
Lithium-ion batteries used in electric vehicles (EVs) are facing issues owing to internal short-circuit (ISC), leading to thermal runaway. In this study, a pseudo-two-dimensional (P2D) model is employed to numerically investigate the effects of charging rate (C-rate) and separator electrical conductivity on the ISC behavior of a lithium-ion cell. The results reveal that as C-rate increases, both the voltage and capacity decrease more rapidly marked by higher solid potential gradient indicating increased internal resistance. These effects further intensified at higher separator conductivity, which facilitates greater ISC current and accelerates cell degradation. Also, the variations in current density and solid-phase lithium concentration become more pronounced at higher C-rates, particularly near the anode–separator interface, indicating increased non-uniformity during ISC conditions. Furthermore, the electrolyte voltage drop intensifies with rising C-rate, contributing to additional polarization. Further, it is observed that the separator conductivity has a significant influence on ISC current, although it shows a minimal effect on the terminal voltage. The value of the ISC current is found to increase with the increase in the value of the conductivity of the separator. Finally, it can be inferred that the lower electrical conductivity of the separator is desirable to prevent ISC of the Li-ion cell. The study highlights that a lower separator conductivity is beneficial in mitigating the severity of ISC events. These findings provide valuable insights for the design of safer lithium-ion cells considering the separator conductivity and operational C-rates.
Ch, Narendra Babu, Paramane, Ashish, Randive, Pitambar
Durable Aluminum Alloys for Brake Disc and Rotor Applications2025-01-03589/15/2025
Lightweight materials are essential in reducing the overall weight and improving the efficiency and performance of ICE and electric vehicles. The use of aluminum alloys is critical in transitioning to a more energy sustainable and environmentally friendly future. The accessible combinations of high modulus to density and strength to weight ratios, as well as their excellent thermal conductivity, make them an ideal solution for overall weight reduction in vehicles, thereby improving fuel efficiency and reducing emissions. Aluminum alloys with high strength and lifetime thermal stability have been industrialized for usage in brake rotor applications. Amongst the most used aluminum alloys with high thermal stability are 2618-T8 and 4032-T6 for use in aerospace and automotive industries, respectively. However, when it comes to prolonging the life of a product at temperatures that exceed 200°C, the properties of these alloys will quickly degrade within the first 300 hours of exposure. Therefore, a new generation of Al-Cu-Mg alloys was developed to further optimize properties and to provide the maximum strength at elevated temperatures with the highest thermal conductivity. Adequate testing exposing them to temperatures up to 300°C for an extended period of time showed that they do not demonstrate significant loss in mechanical strength. In addition, simulations to predict the aluminum strength loss during braking were generated and results are cross compared to cast iron, SS and 304L.
Duchaussoy, Amandine, Lorenzino, Pablo, Franklin, Jack, Tzedaki, Maria
Evaluating Safety Behavior of Li-Ion Batteries Regarding Negative Electrode Composition2025-24-01499/7/2025
Li-ion battery performance is highly dependent on the electrode materials. The composition of the negative and positive electrodes influences crucial aspects of the Li-ion cell, including energy density, ageing behavior and thermal stability. Recent Li-ion technologies include the use of composite graphite-silicon negative electrodes to improve the energy storage capacity of the otherwise graphite-only negative electrode. This article evaluates the impact of negative electrode composition (standard graphite vs. Si-Gr) on the performance of two recent technologies of Li-ion batteries from the same manufacturer, focusing on electrical performance and safety behavior. The studied technologies are the LG M50LT and LG M58T, the latest one introducing a considerable increase of capacity, passing from 4.80 to 5.65 in nominal capacity. This article abords the comparison of both technologies in electric performance, electrode composition, cell design and thermal stability. Electrical characterization confirmed that the LG M58T cells possess 12.5% more capacity than the LG M50LT technology. Material characterization proved the key difference between both technologies: Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX) confirmed that the LG M50LT negative electrodes are composed of graphite, while the M58T features a blended graphite-silicon oxide (SiOx) electrode. After the analyses regarding cell characterization, the capacity increase of the LG M58T technology was attributed to the presence of silicon particles in its negative electrode composition. Safety tests showed that critical events of the exothermic chain reaction during thermal runaway occurred at similar temperatures for both technologies. Nonetheless, maximal pressure reached during thermal runaway and mass loss during the thermal event were higher for the M58T cells. These first safety results indicate a higher reactivity on the M58T technology related to the higher capacity of the cell.
Cruz Rodriguez, Jesus Armando, Lecompte, Matthieu, Redondo-Iglesias, Eduardo, Pelissier, Serge, Abada, Sara
Enabling Near-Zero Emissions and Superior Efficiency in Large-Bore, Medium-Speed Engines with a Hydrogen-Argon Power Cycle2025-24-00019/7/2025
Combustion engines operating on a hydrogen-argon power cycle (H-APC) offer potential for superior thermal efficiency with true zero exhaust emissions. The high specific heat ratio of argon allows extrapolation of the theoretical efficiency of the Otto cycle to almost 90%. However, this potential is significantly constrained by challenges in combustion control, excessive thermal loading, and system integration, particularly regarding argon recovery. This study investigates these trade-offs, within the context of real-world engine-based peaking power plants. An experimentally validated 1D-simulation model of a prototype Wärtsilä 20 DF engine serves as reference for analysis of a retrofit incorporating a closed-loop argon cycle, with dedicated H₂ and O2 injectors, a water condenser and water separator. Engine performance is evaluated at reference operating point of 75% load, considering pre-ignition, peak pressure and exhaust temperature constraints, condenser limitations, and impurity accumulation. Argon emerges as the best monoatomic gas for H-APC. Helium, the second-best candidate, offers superior thermal conductivity and specific heat, but its low density and molecular weight reduce power output. A 90% argon and 10% oxygen mixture offers the optimal trade-off between power output, efficiency, and durability. A compression ratio of 11.90:1 ensures stable combustion within design constraints, while stoichiometric operation and condenser inlet pressure of 3.23 bar enhances performance, achieving the best indicated gross efficiency of 59.10%. This is over 10 percentage points better than the reference engine at 75% load. Nevertheless, practical implementation is limited by pumping losses in a packaging-optimized argon-path layout, reducing extractable efficiency to 56.70%. Furthermore, just 2% impurities in fuel/oxidizer stream causes progressive efficiency decline, falling below the reference threshold after approximately 10 minutes of operation. This highlights the necessity of a membrane-based separator and system volume optimization. The findings establish a validated computational framework for optimizing closed-loop hydrogen combustion and provide valuable insights for progressing demonstrator development.
Ahammed, Sajid, Ahmad, Zeeshan, Mahmoudzadeh Andwari, Amin, Kakoee, Alireza, Hyvonen, Jari, Mikulski, Maciej
Thermal Stress Reduction in Diesel Engine Pistons Using Semitransparent Ceramic Coatings: A 3D Numerical Study with OpenFOAM2025-24-00039/7/2025
This research focuses on the thermal analysis of internal combustion engine pistons, evaluating the effects of high-temperature exposure during operation. A three-dimensional numerical study is conducted using OpenFOAM, modifying the software’s governing equations to analyze temperature distribution in different piston geometries. The study aims to assess the spatial temperature variation within the entire volume of the piston, providing a detailed understanding of heat transfer mechanisms. A multilayer approach is implemented, considering various configurations of ceramic coatings with distinct thermal and optical properties. The investigation incorporates an internal heat source model, where the heat absorption characteristics of the coating material influence the thermal behavior of the system. By evaluating aluminum- and titanium-based ceramic coatings, the study examines how semitransparency and heat radiation absorbance affect heat accumulation and transfer. The results highlight the significance of optical properties in modifying the thermal response of coated surfaces, demonstrating that coatings with heat radiation absorbance capabilities provide enhanced thermal insulation compared to traditional ceramic coatings. The numerical solution of the heat equation, incorporating experimental absorbance data, reveals that coatings with optimized optical properties reduce heat penetration into the piston substrate more effectively than models based solely on thermal conductivity. The findings contribute to the development of advanced thermal barrier coatings, improving the efficiency and durability of internal combustion engine components.
Gutierrez, Marcos, Taco, Diana, Bösenhofer, Markus
A Successful Catalyst Design for Advanced Zinc-Iodine BatteriesTBMG-532066/1/2025
Aqueous zinc-ion batteries (ZIBs) have attracted extensive attention due to their high safety, abundant reserves, and environmental friendliness. Iodine with high abundance in seawater (55 μg L-1) is highly promising for fabricating zinc-iodine batteries due to its high theoretical capacity (211 mAh g-1) and appropriate redox potential (0.54V). However, the low electrical conductivity of iodine hinders the redox conversion for an efficient energy storage process with zinc. Additionally, the formed soluble polyiodides are prone to migrate to the Zn anode, leading to capacity degradation and Zn corrosion.
Predictive Modeling of Surface Roughness, Tool Wear, and Cutting Temperature in High-Speed Turning under Sustainable Machining Environments05-19-01-00075/24/2025
The utilization of Inconel 718 is increasing daily in stringent operating conditions such as aircraft engine parts, space vehicles, chemical tanks, and the like due to its physical properties such as maintaining strength and corrosion resistance at higher temperature conditions. Besides, Inconel 718 is one of the difficult materials for machining because of maintaining its strength at elevated temperature, which generates higher cutting force leading to observed multiple tool wear mechanisms that affect the surface quality; lower thermal conductivity of materials produces high temperature generation that impacts the tool performance by reducing tool life. In addition, the presence of carbides and high hardness of IN 718 affects the machining performance. Therefore, in this view, this article describes the effect of cutting environments and machining parameters on the machining of Inconel 718 and optimizes the cutting conditions for sustainable machining. Three input parameters namely cutting speed, feed rate, and depth of cut as well as three cutting environments such as flood cooling, MQL (minimum quantity lubrication), and NMQL (nano minimum quantity lubrication) were considered for the experimentation. Experimental runs were designed based on the Taguchi method, which had a total of 27 runs performed on the CNC turning. TiAlN-coated triangular-shaped cutting inserts were used for all experimental runs. This research study addresses three output parameters namely surface roughness, tool wear, and cutting temperature. Finally, the cutting condition was optimized by using the Taguchi method and predicting the relationship between the input parameters and the output parameter using the RSM method. Experimental results observed that the NMQL cutting environment shows better machining performance than the MQL and flood cooling due to the presence of nanoparticles in the base fluid, which act as heat carriers. Whereas minimal surface roughness 0.4 μm and lower cutting temperature (85°C) were observed at low cutting speed, feed rate, and depth of cut (78.54 mm/min, 0.1 mm/rev, 0.1 mm) combination and minimum tool wear was found in moderate cutting speed conditions (117.81 mm/min, 0.1 mm/rev, 0.1 mm). Whereas highest cutting temperature and tool wear such as 130°C and 0.3 mm, respectively, observed in flood cooling environment at the cutting speed (157.08 mm/min, 0.3 mm/rev, 0.3 mm). Using the Taguchi method optimum condition was found in the NMQL cutting environment, at the combination of cutting speed 78.54 m/min, feed 0.1 mm/rev, and depth of cut 0.1 mm. From the ANOVA results, develop the predictive model whose results match with the experimental result. Finally, regression model was developed between the response variable and input parameters.
Mane, Pravin Ashok, Dhawale, Pravin A., Nipanikar, Suresh, Khadtare, Avinash N.
Wear Protection for Electrified Transmissions Using e-Fluids without Active Sulfur04-18-03-00155/8/2025
In electrified drivetrains, lubricants are commonly in contact with the motor and other electrical components as well as the gears and bearings. Copper, present in these electrical components, is susceptible to corrosion by fluids containing active sulfur, which can lead to catastrophic failure of the unit. Lubricating fluids for electric vehicles (referred to as e-fluids) must not cause corrosion and must maintain high performance while having suitable electrical conductivity, material compatibility, and heat transfer properties. We describe a new formulation without active sulfur that has recently entered the market, which can protect against copper corrosion. We show that this e-fluid can provide suitable wear protection under field trial conditions, and that the e-fluid provides improved wear protection in bearing (FE-8) tests compared to a traditional extreme pressure axle fluid (API GL-4). Surface analysis (X-ray photoelectron spectroscopy) measurements of the component surfaces after testing show that the wear protection arises from the formation of phosphate tribofilms, which are not present after testing with the traditional fluid. We show that the e-fluid provides high resistance to micropitting by gear (FZG) testing. Surface analysis measurements following reciprocating (TE-77) tribological testing again show that the wear protection arises from the formation of phosphate tribofilms, this time comparable to those produced by traditional driveline fluids.
Hopper, Elizabeth R., Williams, Megan S., Gahagan, Michael
Eddy Current Inspection of Circular Holes in Nonferrous Metallic Aircraft Engine HardwareAS4787A (Current)5/2/2025
This SAE Aerospace Standard (AS) establishes minimum requirements for eddy current inspection of circular holes in nonferrous, metallic, low conductivity (less than 5% IACS) aircraft engine hardware with fasteners removed. The inspection is intended to be performed at maintenance and overhaul facilities on engine run hardware.
AMS K Non Destructive Methods and Processes Committee
Conceptual Design of a Superconducting Aero Electric Engine System2025-01-01465/2/2025
The goal of the development of an electric aircraft engine is to create an aircraft system that achieves ultimate efficiency using hydrogen fuel instead of fossil fuels. Therefore, it is necessary to focus on reducing weight as much as possible, and this paper describes the approach to such fuel cell-powered aircraft. The authors have adopted a superconducting coreless rotating electric machine with an integrated hydrogen tank and are pursuing a target of 70kg or less for the main components of a 2MW rotating electric machine. High-temperature superconducting cables have zero electrical resistance and can carry a very high current density, but the alternating current (AC) loss generated when used in AC has been an issue in their application to rotating electric machines. In 2023, The SCSC cable was developed to be a low-AC-loss, robust, and high current cable concept, in which copper-plated multifilament coated conductors are wound spirally on a core. In addition to using this superconducting cable, the structure is designed to minimize the weight required to maintain the cryogenic state, and it consists of a single structure that combines a hydrogen tank and a rotating electric motor. This new type of superconducting rotating machine combines flux concentrated type field rotor technology and canned motor technology and provides a seal structure and bearings that make it practical. To put superconducting rotating machines to practical use in electric aircraft engines, it is necessary to transmit high currents from fuel cells, and this system proposes a flexible superconducting cable for power transmission with a hydrogen supply function that combines light weight and flexibility. As a result of performance estimation, we have confirmed that this superconducting rotating machine has the potential to improve performance by more than 10 times compared to our conventional products.
Oyori, Hitoshi, Sakurai, Sho, Kusase, Shin, Yoshida, Yukihiro, Yoshinaga, Seiichiro, Nose, Hiroyuki, Amemiya, Naoyuki
Material Adapted Method for the Repair of Curved Thermoplastic Composite Structures by Induction Welding of Patches2025-01-01655/2/2025
Thermoplastic fiber-reinforced polymer composites (TPC) are gaining relevance in aviation due to their high specific strength, stiffness, potential recyclability and the ability to be repaired thanks to their meltability. To maximize their potential, efficient repair methods are needed to maintain aircraft safety and structural integrity. This article introduces a novel repair technique for damaged TPC structures, involving the joining of a repair patch with induction welding using a susceptor material. The susceptor consists of a material with high electrical conductivity and magnetic permeability and therefore reacts stronger to the electromagnetic field than the composite, even if the composite is carbon fiber based. I. e. the thermal energy is specifically concentrated in the repair area. In this study, the susceptor was placed on the patch and also in the welding zone. The repair process begins by identifying and preparing the damaged area, followed by precise scarfing. Care is taken to ensure that the surrounding material remains intact and that an exact stepped structure is created, which enables an optimal bonding with the patch to be used. The customized patch, which fits perfectly in terms of shape and material to the area to be augmented, is then inserted into the structure. Induction heating melts the thermoplastic matrix to join the patch with the structure using a flexible induction mat. The repair process is monitored using thermocouples to ensure even heat distribution, while pressure is maintained through a vacuum bag. The vacuum bag ensures a uniform pressure distribution even on complex curved structures. This adaptable repair method can handle individual damages. It was tested on flat carbon fiber-reinforced polyphenylene sulfide (CF-PPS) structures, showing repairs with nearly 70 % of the original performance for copper mesh susceptors. Optical tests of the specimens confirmed a bonding zone with minimal defects. Overall, this method offers a material-compatible solution for TPC repair in future aviation, advancing aerospace maintenance and offering significant potential for future industry use.
Geiger, Markus, Glaap, Anton, Schiebel, Patrick, May, David
Hose Assembly, Convoluted Polytetrafluoroethylene, Metallic Reinforced, Low Pressure, Up to 400 °F, AircraftAS1227C (Current)4/14/2025
This SAE Aerospace Standard (AS) defines the requirements for a convoluted polytetrafluoroethylene (PTFE) lined, metallic reinforced, hose assembly suitable for use in aerospace fluid systems at temperatures between -65 °F and 400 °F for Class 1 assembly, -65 °F and 275 °F for Class 2 assembly, and at operating pressures per Table 1. The use of these hose assemblies in pneumatic storage systems is not recommended. In addition, installations in which the limits specified herein are exceeded, or in which the application is not covered specifically by this standard, shall be subject to the approval of the procuring activity.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Virtual Evaluation of Ceramic Glow Plug Design using Multiphysics Simulation Approach2025-01-83674/1/2025
A glow plug is generally used to assist the starting of diesel engines in cold weather condition. Low ambient temperature makes the starting of diesel engine difficult because the engine block acts as a heat sink by absorbing the heat of compression. Hence, the air-fuel mixture at the combustion chamber is not capable of self-ignition based on air compression only. Diesel engines do not need any starting aid in general but in such scenarios, glow plug ensures reliable starting in all weather conditions. Glow plug is actually a heating device with high electrical resistance, which heats up rapidly when electrified. The high surface temperature of glow plug generates a heat flux and helps in igniting the fuel even when the engine is insufficiently hot for normal operation. Durability concerns have been observed in ceramic glow plugs during testing phases because of crack formation. Root cause analysis is performed in this study to understand the probable reasons behind cracking of the glow plug when it is subjected to in-operation conditions and design optimization is also suggested to reduce the risk of cracking. Multiphysics based simulation methodology is developed to capture the overall behavior of glow plug during manufacturing and in-operation conditions. Rapid heating of glow plug by passing of electricity is captured using a coupled electro-thermal simulation approach and the stress developed due to thermal gradient is also captured by a thermo-structural analysis. Effect of different operational parameters over the directional stresses are studied using the developed simulation approach to optimize the glow plug design. Stress comparison results between the existing model and the proposed optimized model is also presented in this paper to demonstrate the improvement in durability behavior of the optimized design compared to the initial design of glow plug. The overall analysis approach, described in this paper can be used as a decision-making tool during initial design stages of glow plug to come up with robust designs.
Karmakar, Nilankan, Orban, Hatem
Numerical Investigation of Gas Diffusion Layer Properties in PEMFC2025-01-83144/1/2025
This study numerically analyzed the gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs). The GDL, composed of carbon fibers and binder, plays a critical role in facilitating electron, heat, gas, and water transport while cushioning under cell compression. Its microstructure significantly influences these properties, requiring precise design. Using simulations, this study explored GDL designs by varying fiber and binder parameters and calculated gas diffusivity under wet conditions. Unlike previous studies, a novel model treated carbon fibers as beam elements with elastic binder connections, closely replicating structural changes under compression. Key properties analyzed include permeability, electrical conductivity, and gas diffusion efficiency under wet conditions. The optimized designs enhanced these properties while balancing trade-offs between electrical conductivity and mass transport. These findings provide valuable guidelines for advancing PEMFC technology.
Ota, Yuki, Dobashi, Toshiyuki, Nomura, Kumiko, Hattori, Takuya, Maekawa, Ryosuke
Thermal Insulation Tiles and Sheets Based on Integration of Recycled Plastic Waste Fibres and Epoxy Resin2025-01-83254/1/2025
Plastic waste, in the past few years, has risen to be one of the most concerning and endangering pollutants to environment and life, making its effective management and reduction a major domain of focus among researchers and industrialists. This comparative study is an attempt to utilize recycled Polyethylene Terephthalate (rPET) fibres combined with Epoxy Resin in various combinations, to provide effective and low-cost insulation in moderate to low requirements. The above-mentioned components serve as viable insulators. Moisture resistance of both materials and temperature resistance of Epoxy resins ranging from 120°C to 150°C (depending upon the grade of Epoxy used) indicate a good stability in harsh external operating environment. While Epoxy resins are not inherently flame retardants, additives are introduced for this purpose in order to render the composite safer to use. Owing to the excellent adhesive properties of the Epoxy resin, the rPET fibres are allowed to bond together firmly and also exhibit good overall strength of the composite and also making sure that the composite will not delaminate or weaken over time. Controlled environmental experiments and mathematical modelling of the real-life conditions have been performed. As a part of this study, multiple configurations of the mentioned composite have been tested experimentally and simulatively with varying overall thickness ranging from 3mm to 15mm. Results show temperature difference of about 12°C, indicating that the composites developed can be used as effective thermal insulators.
Purihella, Sri Sai Krishna, Pali, Harveer Singh, Kumar, Piyush, Sharma, Ved Prakash
Materials Innovation in Thermal Management: Advancing Aluminum Alloy Technologies for the Next-Generation Electrical Vehicle Battery Cold Plate2025-01-81624/1/2025
The rapid expansion of the global electric vehicle (EV) market has significantly increased the demand for advanced thermal management solutions. Among these, the battery cold plate is a critical component, essential for maintaining optimal battery temperatures and ensuring efficient operation. As EV batteries increase in size, the thermal management requirements become more complex, necessitating the development of new alloys with enhanced strength and thermal conductivity. These advancements are crucial for the effective dissipation of heat and the ability to withstand the mechanical stresses associated with larger and more powerful batteries. The evolving performance demands of EVs are driving material innovation within the thermal management sector. This study aims to explore the global heat exchanger market trends from a material perspective, focusing on the evolution of the mechanical and thermal properties. Specifically, we investigated the transition from the traditional AA3003 alloy to the modified AA3xxx alloys, and the potential for AA6xxx alloys to deliver further advancements. The mechanical properties of these alloys were assessed after both natural and artificial aging processes. Notably, the yield strength of the AA6xxx alloy increased by 128.7% after the artificial aging process. Additionally, the thermal conductivity of the alloys was evaluated to identify materials that could provide significant improvements in heat exchanger applications. The thermal conductivity of the AA6xxx alloy increased by 10% after artificial aging. By comparing the performance of the traditional and modified alloys, this study provides insights into the future direction of material development for thermal management in the EV market. The results underscore the importance of material innovation in addressing the growing demands of the next-generation heat exchanger market within the EV industry.
Jalili, Mehdi, Wang, Xu, Razm-poosh, Hadi
Liquid Viscosity Decoupling Measurement Based on U-Shaped Tungsten Wire Sensor2025-01-84604/1/2025
In this paper, based on the cylindrical flow theory of incompressible viscous fluids and the equivalent circuit model of resonant sensing elements, a theoretical model for the measurement of liquid viscosity with a U-Shaped tungsten wire resonance sensor was established. This model can measure the liquid viscosity independently without liquid density or coupled detection of liquid density. The experimental results show that the decoupling of liquid viscosity and its density can be achieved at Re<1. The liquid viscosity is strongly linear with the resonant conductance. The viscosity measurement error is less than 7.24% in the viscosity range of 7.235cP to 85.2cP.
Shan, Baoquan, Shen, Yitao, Yang, Jianguo, Wu, Dehong
Optimization Method of Phase Change Energy Storage Device for Electric Vehicle Batteries based on Numerical Simulation2025-01-86034/1/2025
Phase change energy storage devices are extensively utilized in latent heat thermal energy storage and hold significant potential for application in the thermal management of automotive batteries. By harnessing the high-density energy storage capabilities of phase change materials to absorb heat released by the batteries, followed by timely release and utilization, there is a substantial improvement in energy efficiency. However, the thermal conductivity of medium and low temperature phase change materials is poor, leading to its inefficient utilization. This paper focuses on optimizing the structure of a phase change heat exchanger in a phase change energy storage device to improve its performance. A basic design of the phase change heat exchanger is used as an example, and fin structure is added to enhance its heat exchange capabilities. A predictive surrogate model is built using numerical simulation, with the dimension and number of fins as design variables, and heat flow density, heat absorption and release time as optimization objectives. This model can utilize lower simulation calculation costs to obtain a continuous mapping relationship between optimization objectives and design variables within a certain range, and has high accuracy and reliability. The fitted design variable distribution surface is used to select any number of design points for verification. The deviation between prediction results and simulation results is less than 4%. Compared with the original design, the optimized design can not only achieve appropriate heat exchange efficiency according to requirements, but also extend the effective heat dissipation time, making the heat dissipation process more stable. The structural optimization method outlined in this paper offers a cost-effective approach to accurate prediction results, demonstrating practical engineering implications for the design of phase change energy storage devices and thermal management of electric vehicle batteries.
Zhang, Haonan, Sun, Mingzhe, Zheng, Haoyun, Zhang, Tianming
Material-Combined Vehicle Brake Disc Design for Enhanced Cooling Performance2025-01-81894/1/2025
The improvement of heat dissipation performance of ventilated brake discs is vital to braking safety. Usually, the technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC), and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC has better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC has poorer heat capacity yet, according to previous studies, it has better thermal stability, which is the ability to ensure its friction factor under high-temperature condition; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake discs using different friction materials and geometry structures. Al-MMC and C-SiC friction layers are compared at the level of material application. At the level of geometric structure, 3mm and 5mm are chosen to be the thickness, and the different simulations of simulation are discussed. For material selection, the material-combined discs have lower friction surface temperatures compared to the use of single materials, and the overall temperature gradient distribution is more uniform; for the selection of the friction layer thickness, the use of the 3mm composite friction layer scheme, regardless of the Al-MMC or C-SiC, has a lower friction surface temperature than the 5mm friction layer scheme. For different friction layer thicknesses, using a 3mm friction layer has a lower friction surface temperature than 5mm regardless of the materials, and the temperature distribution is more uniform. However, due to the increased cast iron content, the 3mm solution is less lightweight than the 5mm solution. Overall, the material combination approaches can offer a significant performance improvement over the single material discs, which contributes to the safety of automotive braking.
Wang, Jiarui, Jia, Qing, Zhao, Wentao, Xia, Chao, Yang, Zhigang
SHIELD BAND, CONNECTOR ACCESSORIES, ELECTRICAL BACKSHELL, CATEGORY 7 (FOR AS85048/82 - /90, /93, /109 - /117 ACCESSORIES)AS85049/128G (Current)2/8/2025
AE-8C1 Connectors Committee
Synthesis and Characterization of Poly (Aniline –Co-Chloroaniline) Polymers and Applications in Automotive Industries as Paint Coatings2025-28-00372/7/2025
Polyaniline (PANI)-polymer based smart paints have emerged as a promising solution for enhancing the durability and performance of automobile surface coatings. These paint coatings offer a superior corrosion resistance, conductivity, and environmental stability, making it an ideal. Here novel copolymers of dodecylbenzene sulfonic acid(DBSA) aided poly (aniline-co-m-chloroaniline) nanocomposites of various compositions were prepared by oxidative method in micellar solution. These nanocomposites were analyzed by using UV-Vis and FT-IR spectroscopic methods. The crystalline nature of the polymer was evidenced through XRD patterns. SEM revealed the presence of particles with spherical morphology 100 nm in diameter. The electrical activity of the doped polymer was found to be content increasing from 3:1 to 3:3 x 10-2 S/cm to 5.64 x 10-7 S/cm with chloroaniline. These copolymers are added as additives in manufacturing of paint. These novel paints offer multiple protective mechanisms, including barrier protection, passivation, inhibition of cathodic and anodic reactions, and electrochemical stabilization. These mechanisms work synergistically to prevent the penetration of corrosive agents and redistribute electrochemical activity across the metal surface, thereby reducing the rate of corrosion. In addition to corrosion resistance, these paints also provide anti-static properties contributing to the overall functionality and longevity of automotive components.
Pachanoor, Vijayanand, Moorthi, Bharathiraja
Grey Relational Analysis for Multi-Objective Optimization in Aerospace Machining of Titanium Grade 192025-28-00472/7/2025
Electrochemical machining (ECM) is a highly efficient method for creating intricate structures in electrically conductive materials, irrespective of their hardness. Due to the growing need for superior products and quick design adjustments, decision-making in production has become increasingly complex. This study focuses on Titanium Grade 19 and proposes creating predictive models using a Taguchi-grey technique to achieve multi-objective optimization in ECM. The experiments are structured based on Taguchi's principles, utilizing Taguchi-grey relational analysis (GRA) to simultaneously optimize several performance indicators, including the material removal rate, surface roughness, and geometric tolerances. ANOVA is employed to assess the significance of process variables affecting these measures. The proposed predictive technique for Titanium Grade 19 outperforms current models in terms of flexibility, efficiency, and accuracy, providing enhanced capabilities for monitoring and control. Additionally, the research explores the use of Titanium Grade 19 in automotive applications, highlighting its importance in industries that require strong, corrosion-resistant materials. Experimental validation confirms a strong correlation between the projected results and actual performance, thereby demonstrating the effectiveness of the proposed approach.
Pasupuleti, Thejasree, Natarajan, Manikandan, Krishnamachary, PC, Katta, Lakshmi Narasimhamu, Silambarasan, R
Development of Composite PCM To Enhance Heat Transfer Rate with the Addition of Nanoparticles in Thermal Energy Storage2025-28-00232/7/2025
This paper explores the augmentation of thermal conductivity in paraffin wax through the incorporation of aluminum oxide (Al2O3) and copper oxide (CuO) nanoparticles, leading to the development of composite phase change materials (PCMs). The objective is to enhance heat transfer rates, crucial for various energy storage applications including industrial waste heat recovery and solar thermal energy storage. Differential Scanning Calorimetry (DSC) testing was employed to experimentally investigate the thermal properties of the resulting nanocomposite PCM. The experimental results reveal that the nanocomposite PCM, composed of 96.14% paraffin wax, 2% aluminum oxide, and 1.6% copper oxide, exhibits 1.35 times increase in heat transfer rate compared to conventional paraffin wax. The integration of nanoparticles into the PCM matrix, facilitated by a magnetic stirrer at 50oC for 4 hours, results in uniform distribution and improved grain morphology, as evidenced by SEM images. Moreover, the composite PCM demonstrates superior performance, surpassing paraffin wax by 1.35 times durin g heating and 1.5 times during cooling, while maintaining similar peak temperatures. The normalized enthalpy of the composite PCM exceeds that of paraffin wax by 1.25 times, highlighting enhanced energy storage capacity. The significant enhancements in thermal conductivity and phase change behavior are attributed to the presence of aluminum oxide and copper oxide nanoparticles. Notably, an optimized composition comprising 96.15% paraffin wax, 2.15% aluminum oxide, and 1.7% copper oxide Considered by mass demonstrates a delicate balance between improved thermal properties and material stability. This study underscores the immense promise of nanoparticles – enhanced composite PCMs as a transformative solution for enhancing thermal energy storage efficiency, with implications for sustainable energy technologies. The results shows that the thermal conductivity improved by 48% and the enthalpy increased by 25%.
Tarigonda, Hariprasad, Kumar, YB Kishore, Kala, Lakshmi K, R L, Krupakaran
Enhancing Disc Brake Performance: Investigating Squeal Noise, Wear, and the Application of Functionally Graded Materials in Brake Rotors2025-28-01622/7/2025
Disc brakes play a vital role in automotive braking systems, offering a dependable and effective means of decelerating or halting a vehicle. The disc brake assembly functions by converting the vehicle's kinetic energy into thermal energy through friction. The performances of the brake assembly and user experience are significantly impacted by squeal noise and wear behaviour. This paper delves into the fundamental mechanisms behind squeal noise and assesses the wear performance of the disc brake assembly. Functionally graded materials (FGMs) are an innovative type of composite material, characterized by gradual variations in composition and structure throughout their volume, leading to changes in properties such as mechanical strength, thermal conductivity, and corrosion resistance. FGMs have emerged as a groundbreaking solution in the design and manufacturing of brake rotors, addressing significant challenges related to thermal stress, wear resistance, and overall performance. These studies evaluate the noise and wear behaviour of disc brake assemblies made with FGMs. The paper also investigates the application of FGMs in brake rotors, highlighting their distinctive properties and the advantages they offer to automotive braking systems. The study underscores the importance of further research and development to fully leverage the benefits of FGMs in enhancing brake system performance.
C V, Prasshanth, S, Gurumoorthy, Bhaskara Rao, Lokavarapu, S, Sridhar, S, Badri Narayanan, Kumar, Ajay, Biswas, Sayan
Cutting-Edge Coating Materials for Dual Fuel Diesel Engines Using Acetylene Aspiration2025-28-01342/7/2025
A diesel engine with a Yttria Stabilised Zirconium (YSZ) thermal barrier layer (TBL) on the piston crown was used in an experiment. The aim of the investigation was to evaluate the influence of the thermal barrier layer on the efficiency and pollution levels of a diesel engine. The selection of YSZ as the coating material was based on its desirable physical properties including a high coefficient of expansion when exposed to heat, low degree of thermal conductivity, and a high Poisson's number. These characteristics make it a suitable material for use in coatings applied to engine components. In addition to their current research, the scientists are also focusing on identifying sustainable substitutes for conventional petroleum fuels. This is because of the growing concern over environmental impacts and the limited availability of fossil fuel resources. The researchers are seeking new options that are both environmentally friendly and capable of meeting the world's energy demands. By exploring alternative energy sources, the team aims to develop more sustainable and efficient solutions for the future. Studies report that an acetylene gas derived from the process of hydrolysis of calcium carbide which in turn being produced from lime stone and coke has similar property to that of hydrogen. As hydrogen implementation in use of internal combustion engine fuel seems to be a mirage. Acetylene could compete the hydrogen in all aspects, in usage of automotive fuel. In the present work, acetylene properties were analysed for being used as a fuel in automotive engine with all safety aspects. A test experiment has been conducted on a modified single cylinder, zirconium coated piston of diesel engine run on two different fuel. The primary energy source was diesel while acetylene gas was introduced as a secondary energy source at varying fixed flow rates. Due to acetylene aspiration, it is revealed from this test analysis that it increases thermal efficiency by 2 – 4 % for diesel fuel and increases NOx emissions by 3.51 – 4.23% as compared to acetylene induction. As compared to baseline diesel operation, the smoke intensity is dropped by 2.8% at 0.25 kg/hr, 8.8% at 0.35 kg/hr, and 18% at 0.45 kg/hr of gas flow rate at maximum load.
Sagaya Raj, Gnana, Natarajan, Manikandan, Pasupuleti, Thejasree
Enhancing Solar Still Productivity with Aluminium Oxide Nanoparticles and Phase Change Materials2025-28-00262/7/2025
The present study is focused on the integration of phase change materials (PCMs) and Al2O3 nanoparticles into solar stills presents a promising approach to enhance their efficiency. This paper explores the design and performance analysis of a solar still system incorporating PCMs and Al2O3 nanoparticles with different concentration like 200ppm and 400ppm. The primary goal is to investigate the impact of these enhancements on the solar still’s productivity and thermal efficiency.The Aluminium Oxide Nanoparticle were synthesized by chemical co-precipitation method. XRD and TEM were used to characterize the aluminum oxide particles. In this study, Aluminum oxide nanoparticles were employed as thermal conductivity materials, while TN+30 were utilized as a phase change material. After taking about 25 (liters) of water, it was discovered that 1 cm was the ideal depth. Compared to PCM, the energy materials TN+30 and Al2O3 increased collection efficiency with 200 ppm and 400 ppm of 21.65% and 32.97%, respectively.
R L, Krupakaran, Sagaya Raj, Gnana, Petla, Ratna Kamala, Kala, Lakshmi K, Anchupogu, Praveen
Investigation on Heat Transfer Properties of Graphene Nanoplatelets Blended Distilled Water-Ethylene Glycol Mixtures in Battery Thermal Management System2025-28-00892/7/2025
This study investigates the heat transfer properties of graphene nanoplatelets (GnPs) blended with distilled water-ethylene glycol (DW-EG) mixtures, focusing on their potential application in battery thermal management systems (BTMS). Compared to other nanoparticles, carbon nanostructures exhibit higher thermal conductivity due to their low density and integrated thermal conductivity. The experimental findings are relevant in that compared with the base fluid, nanofluid samples had heat transfer capability. The physicochemical characteristics of investigated GNP were characterized using a Scanning Electron Microscope (SEM), pH and UV–Vis spectrophotometry. The thermal conductivity and physical properties of graphene platelets having the specific surface area of 500 m2/g in the base fluid of Distilled Water-Ethylene Glycol (DW-EG 70:30) and 100 % vol. of Ethylene Glycol (EG 100) were determined after 120 minutes of sonication time. The graphene nanofluids with the platelet concentrations of 0.025, 0.05, 0.075, and 0.1 wt% were investigated for the dispersion properties. The stability of nanofluid was examined using a zeta potential and UV-visible spectrophotometer. According to the thermal conductivity facts, dispersed nanoparticles always improve the heat conductivity of the DW-EG 70:30s base fluid, with the greatest improvement occurring at a concentration of 0.1 weight per cent GNPs. The study suggests that the GnP-infused nanofluids exhibit excellent heat transfer performance, making them promising candidates for enhancing the efficiency of BTMS in electric vehicles, providing a cost-effective and efficient solution for thermal management.
S, Palanisamy, Selvan, Arul Mozhi
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