Browse Topic: Conductivity
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
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
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
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
Gray cast iron (GJL) is one of the oldest cast iron materials and is still in use in many applications in the automotive industry due to its good characteristics, in relation to lubrication, heat conductivity and damping. Engine parts particularly benefit from these parameters. Nevertheless, the design of these components has always been challenging, in terms of maximizing material utilization for lightweight designs for components under cyclic loading. In particular, with regard to the influence of the statistical (component size), geometrical (notches) and technological (microstructural) size effects, the existing guidelines and literature lack the necessary information to provide a comprehensive understanding of the cyclic material behavior of GJL materials. Within a comprehensive study, different GJL materials have been investigated at Fraunhofer LBF to provide more detailed information regarding the influence of size effects on fatigue strength. Accordingly, a variety of specimen
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
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
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.
A tested method of data presentation and use is described herein. The method shown is a useful guide, to be used with care and to be improved with use.
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
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
Electrochemical machining (ECM) is a highly efficient method for creating intricate structures in electrically conductive materials, regardless of their hardness. Due to the growing demand for superior products and the necessity for quick design adjustments, decision-making in the manufacturing industry has become increasingly complex. This study specifically examines Titanium Grade 19 and suggests the creation of an Adaptive Neuro-Fuzzy Inference System (ANFIS) model for predictive modeling in ECM. The study employs a Taguchi-grey relational analysis (GRA) methodology to attain multi-objective optimization, with the goal of concurrently maximizing material removal rate, minimizing surface roughness, and achieving precise geometric tolerances. Analysis of variance (ANOVA) is used to assess the relevance of process characteristics that impact these performance measures. The ANFIS model presented for Titanium Grade 19 provides more flexibility, efficiency, and accuracy in comparison to
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
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
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
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
This study determined the gel point of methanol-water-sodium stearate mixed gels at various concentrations of water and gelling agent by monitoring turbidity changes during the sol-gel transition. The gel points determined by turbidity measurements were further validated by monitoring changes in electrical conductivity during the sol-gel process at various concentrations of water and gelling agent. Molecular dynamics simulations were also conducted to further corroborate the gel points determined experimentally. The turbidity test results showed that the gel point was 20°C for the 3% gelling mixture and 35°C for the 5% gelling mixture. Mixed gels with 10% water content and 3% gelling agent content have a gel spot of 33°C.The electrical conductivity tests revealed that the average gel points for mixed gels with different water contents were 16.75°C (0%), 25.1°C (5%), and 32.4°C (10%). The average gel points for different gelling agent contents were 16.75°C (3%), 23.55°C (4%), and 38.75
The inductance parameter is important for the flux regulation performance of the hybrid excitation motor, and the axial structure leads to the change in the inductance parameter of the axial-radial hybrid excitation motor (ARHEM). To clarify the inductance characteristic of the ARHEM with different winding construction and the mutual coupling effect between the axial excitation and permanent magnet excitation on the inductance. Firstly, the structure of the ARHEM is presented. Secondly, the self and mutual inductance characteristics of ARHEM are analyzed using the winding function method. Then, the influence of the axial excitation structure on the armature reaction field and saliency ratio of ARHEM. On this basis, the mechanism of the mutual coupling, between the axial excitation and permanent magnet field under different excitation currents on the main air gap magnetic field, and the inductance of ARHEM with fractional slot are revealed.
To explore the heat and mass transfer processes within the low-temperature catalyst layer, a coupled heat and mass transfer lattice Boltzmann model and electrochemical model were established, creating a pore-scale model for heat and mass transfer in the catalyst layer. The influence of the catalyst layer parameters was investigated. The results indicate that as time progresses, heat gradually accumulates at the top of the catalyst layer (CL) and is transmitted towards the bottom. Once oxygen enters the CL, it quickly fills the pores within the CL, resulting in a rapid decrease in oxygen concentration within the ionomer. As the platinum volume fraction increases, there is a significant rise in temperature across the entire calculation domain. With the increasing platinum volume fraction, the current density also increases rapidly due to the larger reaction area. When the carbon volume fraction is 0.15, more oxygen enters the ionomer to participate in reactions, and the large porosity
The solar-based hybrid automotive vehicle represents a trend marked by technological excellence, offering an efficient, cost-effective, and eco-friendly solution. Besides, the enhancement of solar absorption due to poor weather is influenced by poor solar power with reduced photocurrent density. This research focuses on enhancing the solar power and photocurrent density of conventional solar cells featuring aluminium-doped zinc oxide thin films (AZO) using the Mist Chemical Vapor Deposition (MIST CVD) process with a zinc acetate precursor solution processed at temperatures ranging from 200 to 400°C. To investigate the effect of AZO on the functional behaviour of solar cells, microstructural studies utilizing scanning electron microscopy and X-ray diffraction reveal the concentration of AZO and the alignment of Al/ZnO peaks as even. As a result, this research demonstrates a 21% increase in solar power output compared to conventional Cadmium Telluride (CdTe) cells, with an improvement in
Magnesium oxide (MgO) nanofluids are of great interest for enhancing the performance in thermal management especially in automotive applications, where efforts have been made to reduce parasitic losses from traditional cooling systems. These findings highlight the effects of Water–ethylene glycol and MgO nanofluids on viscosity and thermal conductivity in specific filling a gap in research that allows to clarify how these states behave at different temperature (T) and concentration (C) conditions. Test results demonstrate that the thermal conductivity of MgO nanofluids improved adequately /while its corresponding change in viscosity remained under control, affirming a significant improvement for energy savings by means heat transfer enhancement using new generation coolants based on this nano-additive. The results also provide useful information for design and development of automotive cooling systems, including real numbers on performance improvements that lead to more efficient and
This research investigates the development of a heat pipe heat exchanger coated with graphene for cooling and purification of automobile exhausts. The heat exchanger directly affects the performance of the engine because proper heat dissipation and transfer can improve engine performance, reduce fuel consumption, and decrease the emission. Moreover, this effect is much more noticeable on coated heat pipes because of the enhanced thermal conductivity and mechanical properties of the graphene films. A heat null emitted by internal combustion engines was used in the experimental setup to test the thermal performance, cooling efficiency, and purification efficiency of the newly designed in-house exhaust simulation system where the new heat pipes were inserted. The results of the experiment show that the heat pipes have very high thermal performance as the efficiency of the heat pipes was calculated to be around 85%. Furthermore, the temperature decrease over the surfaces of the heat
Cold thermal energy storage using phase changing materials is being researched to find freezing and thawing points. The use of inorganic hydrated salts, a type of phase changing material (PCM) used in cold energy storage systems without the use of existing renewable energy systems, allows for a longer cooling effect and saves energy. A high volumetric storage density and relatively high thermal conductivity make hydrated salts suitable materials for thermal energy storage. They can be used only as inorganic mixtures or else they can also be used as eutectic mixtures, which involve mixtures of inorganic–inorganic salts or simply a combination of two or more inorganic salts. This research deals with eutectic mixtures, which are 4% KNO3 + 96% H2O, 4% NaHCO3 + 96% H2O, and 2% KNO3 + 2% NaHCO3 + 96% H2O. Three different novel eutectic mixtures were examined and found a suitable mixture for a cold thermal energy system. An efficient phase change approach involving 2% KNO3 + 2% NaHCO3 + 96
This specification covers the requirements for a low-electrical-resistance chemical conversion coating on aluminum and aluminum alloy parts.
Nanofluids have emerged as effective alternatives to traditional coolants for enhancing thermal performance in automotive applications. This study conducts a comparative analysis of the viscosity and thermal conductivity of ZnO and Cu hybrid nanofluids. Nanofluids were prepared with ZnO and Cu nanoparticle concentrations of 0.1%, 0.3%, and 0.5% by volume and were characterized over temperatures ranging from 25°C to 100°C. The results demonstrate that ZnO and Cu hybrid nanofluids achieve an increase in thermal conductivity by up to 22% and 28%, respectively, compared to the base fluid. Concurrently, the viscosity of these nanofluids increases by up to 12% at the highest concentration and temperature. This study addresses a critical research gap by investigating the combined effects of ZnO and Cu nanoparticles in hybrid nanofluids, an area that has been underexplored. By providing new insights into optimizing both thermal conductivity and viscosity, this research contributes to the
In this study, we investigate the thermal conductivity optimization of nanodiamond nanofluids for application in high-performance automotive engines. Nanodiamond particles, known for their superior thermal properties and stability, are dispersed in a base fluid composed of ethylene glycol and water. Various concentrations of nanodiamonds are prepared to evaluate their impact on thermal conductivity and viscosity. The experimental setup includes precise measurements of thermal conductivity using the transient hot-wire method and viscosity using a rotational viscometer over a temperature range of 25°C to 100°C. The results demonstrate significant enhancements in thermal conductivity with acceptable increases in viscosity, suggesting the potential of nanodiamond nanofluids in improving engine cooling efficiency. The study concludes with recommendations for future research to explore the long-term stability and performance of these nanofluids in real-world automotive applications.
This study points to potentiality of studying Aluminum Oxide (Al2O3) nanofluid on viscosity (μ) and thermal conductivity (K) for automotive cooling system. The Al2O3 nanoparticles dispersed in 50:50 ethylene glycol-water with5 varying concentrations of 0.1, 0.2, 0.3, 0.4 and 0.5 vol%. The viscosity at 25°C, 40°C, 60°C and 80°C was measured by using a Brookfield viscometer; and thermal conductivity was measured by the transient hot wire method. The results indicate that the viscosity increases with the concentration of nanoparticles but decreases with the temperature. Due to comparative importance of thermal conductivity with increasing temperatures and nanoparticle concentrations. In nanofluid Al2O3 can enhance heat transfer automotive cooling system can be good performance and efficient as well as engine, in 0.5% concentration, thermal conductivity at 25°C and increase 27% at 60°C, paranormal found for development and Al2O3 nanofluids apply can be effective improvement at heat
In this study, the viscosity and thermal performance of nanofluids based on ZnO-MgO mixed oxide nanoparticles added in different concentrations to ethylene glycol-water mixture are characterized with potential applications in engine cooling. The work began with two needs: the increasing importance of better heat removal in automotive engines, where traditional coolants struggle to adequately maintain good thermal conductivity but at low viscosity to acceptable levels; and a chance opportunity for exploration provided by MMD/MILab Engineer Andrew Cricee. The work wants to improve the cooling properties, but still keeping good fluidity by integrating ZnO-MgO nanoparticles. Preparation method the preparation of ZnO-MgO nanofluids was done using volume concentrations of 0.1%, 0.3% and 0.5%. To determine chemical properties, viscosity measurements were made on the Dragonfly using a Brookfield viscometer at temperatures ranging from 25 ° C to 80 ° C while varying the nanoparticle
The research introduces the thermal properties of silicon dioxide (SiO2) nanofluids and the promising application of these fluids in hybrid vehicle cooling systems. How to make fluids is simply to disperse a 50-50 mixture of both Ethylene Glycol and Water; into this solution add SiO2 nanoparticles concentration ranges from 0.1% up to 0.5% volume according desired properties or material characteristics etc. When viscosities and thermal conductivities of nanofluid were measured over the temperature range from 25 to 120 °C using Brookfield viscometer and transient hot-wire method; results were as follows: Viscosity of SiO2 nanofluids at 120°C higher concentrations 0.5%, more viscous fluids, thermal conductivity also rose with results, although there was a plateau at around 40% increase compared to that of water-based slurries. At 0.5% concentration, thermal conductivity increased by up to 20% at 120 °C, compared with the value of pure ethylene glycol. These results suggest that SiO2
Recently, there has been a growing emphasis on Thermal Management Systems (TMS) for Lithium-ion battery packs due to safety concerns related to fire risks when temperatures exceed operating limits. Elevated temperatures accelerate electrochemical reactions, leading to cell degradation and reduced electronic system performance. These conditions can cause localized hotspots and hinder heat dissipation, increasing the risk of thermal runaway due to high temperatures, flammable gases, and heat-producing reactions. To tackle these issues, many automotive manufacturers employ indirect liquid cooling techniques to maintain battery pack and electronic system temperatures within safe limits. Engineered nanofluids, particularly those containing multi-nanoparticles dispersed in water and ethylene glycol, are being explored to enhance electrical safety in case of accidental exposure to electrical systems in EVs. This paper focuses on the experimental characterization of nanofluid containing
Wire Electrical Discharge Machining (WEDM) is an essential manufacturing process used to shape complex geometries in conductive materials such as cupronickel, which is valued for its corrosion resistance and electrical conductivity. The aim of this explorative study is to enhance the efficiency and precision of machining by creating a specialized predictive model using an Adaptive Neuro-Fuzzy Inference System (ANFIS) for cupronickel material. The study examines the intricate correlation between process variables of the WEDM (Wire Electrical Discharge Machining) technique, such as pulse-on time (Ton), pulse-off time (Toff), and discharge current, and crucial machining responses, including surface roughness, material removal rate. Data is collected through systematic experimentation in order to train and validate the ANFIS predictive model. The ANFIS model utilizes the collective learning capabilities of neural networks and fuzzy logic systems to precisely forecast machining responses by
Growing demand for fuel-efficient vehicles and lower CO2 emissions has led to the development of lightweight materials. Aluminum composites are being used to achieve lightweighting to improve performance, efficiency, and sustainability across various industries. The unique properties of aluminum composites make them an attractive choice for researchers and designers looking to optimize their products. Reinforcement materials play a vital role in the development of these composites, acting as barriers to dislocation movement within the aluminum matrix. This effectively strengthens the material and prevents deformation under load, resulting in increased tensile strength and fatigue resistance. Additionally, aluminum composites exhibit improved thermal and electrical conductivity, making them suitable for automotive applications. In this study, metal matrix composites (MMCs) of aluminum 7075 alloys were developed using silicon carbide (SiC) and flyash as reinforcements. Three different
The effectiveness of immersion cooling for the thermal management of Electric-Vehicle (EV) batteries is crucially influenced by the thermophysical and rheological properties of the heat-transfer liquid. This study emphasizes upon the design requirements for such a fluid in terms of bulk properties, i.e., high electrical resistivity and thermal conductivity, low viscosity, but also relevant to the rheological properties maximizing the heat transfer rate. Key concepts of the implemented research constitute: (i) the promotion of vortical motion in the laminar flow regime, which, in turn, enhances heat transfer by disrupting boundary layers; (ii) vortex stabilization through the addition of viscoelasticity-inducing agents in the base heat-transfer liquid. To improve cooling efficiency, the primary objective is to maximize the achievable heat transfer rate for minimal pumping losses. Hence, a multi-objective optimization process must be set in place where the optimal coolant rheology is
Niobium (Nb) alloyed Grey cast iron in combination with Ferritic Nitrocarburize (FNC) case hardening heat treatment is proposed to improve wear resistance and reduce brake dust generation of brake rotors. Standard Eutectic and Hypereutectic Grey irons alloyed with Niobium were evaluated in comparison to baseline unalloyed compositions. Brake speed snub sensitivity tribological testing was performed on a matrix including Niobium alloyed, Unalloyed, FNC, Non FNC, Non-Asbestos Organic (NAO) friction and Low metallic (Low Met) friction materials. Full size brake rotors were evaluated by Block Wear and Corrosion Cleanability. Improved wear, corrosion resistance and reduced brake dust debris were demonstrated by the Niobium alloyed FNC brake rotor combinations. Corrosion is an important consideration when evaluating brake performance. Combining cyclic corrosion and brake rotor testing provides the best comparison with field exposure.
To advance soft robotics, skin-integrated electronics, and biomedical devices, researchers have developed a 3D printed material that is soft and stretchable — traits needed for matching the properties of tissues and organs — and that self-assembles. Their approach employs a process that eliminates many drawbacks of previous fabrication methods, such as less conductivity or device failure.
This SAE Aerospace Information Report (AIR) provides guidance on using environmental, electrochemical, and electrical resistance measurements to monitor environment spectra and corrosivity of service environments, focusing on parameters of interest, existing measurement platforms, deployment requirements, and data processing techniques. The sensors and monitoring systems provide discrete time-based records of (1) environmental parameters such as temperature, humidity, and contaminants; (2) measures of alloy corrosion of the sensor; and (3) protective coating performance of the sensor. These systems provide measurements of environmental parameters, sensor material corrosion rate, and sensor coating condition for use in assessing the risk of atmospheric corrosion of a structure. Time-based records of environment spectra and corrosivity can help determine the likelihood of corrosion to assess the risk of corrosion damage of the host structure for managed assets and aid in establishing
The use of aluminum to manufacture injection molds aims to maximize the productivity of plastic parts, as its alloys present higher heat conductivity than tool steel alloys. However, it is essential to accurately control the injection molding parameters to assure that the design tolerances are achieved in the final molded plastic part. The purpose of this research is to evaluate the use of aluminum alloys in high-volume production processes. It delves into the correlation between the type of material used for mold production (steel or aluminum) and the thickness of the injected part, and how these variables affect the efficiency of the process in terms of the quantity and quality of the produced parts. The findings suggest that replacing steel molds with aluminum alloys significantly reduces injection molding cycle time, the difference ranging from 57.1% to 72.5%. Additionally, the dimensional accuracy and less distortion provided by aluminum have improved product quality. In case of
The Selective Laser Melting (SLM) process is employed in high-precision layer-by-layer Additive Manufacturing (AM) on powder bed and aims to fabricate high-quality structural components. To gain a comprehensive understanding of the process and its optimization, both modeling and simulation in conjunction with extensive experimental studies along with laser calibration studies have been attempted. Multiscale and multi-physics-based simulations have the potential to bring out a new level of insight into the complex interaction of laser melting, solidification, and defect formation in the SLM parts. SLM process encompasses various physical phenomena during the formation of metal parts, starting with laser beam incidence and heat generation, heat transfer, melt/fluid flow, phase transition, and microstructure solidification. To effectively model this Multiphysics problem, it is imperative to consider different scales and compatible boundary conditions in the simulations. In this paper, we
Lithium-ion (Li-ion) batteries employ binders that encounter challenges such as poor conductivity and expansion during charging. In a recent study, scientists have developed a high-performing binder using poly(vinylphosphonic acid) for silicon oxide-based anodes in Li-ion batteries. This binder offers enhanced performance as demonstrated by the superior durability, and discharging capacity of the anodes compared to conventional options. With patents filed internationally, this technology holds promise for broader applications in electric vehicles and beyond.
Advanced two-dimensional (2D) materials discovered in the last two decades are now being produced at scale and contribute to a wide range of performance enhancements in engineering applications. The most well known of these novel materials is graphene, a nearly transparent nanomaterial comprised of a single layer of bonded carbon atoms. In relative terms, it has the highest level of heat and electrical conductivity, protects against ultraviolet rays, and is the strongest material ever measured. These properties have made graphene an attractive potential material for a variety of applications, particularly for transportation-related uses, and especially for automotive engineering. The goal of drastically reducing greenhouse gas emissions has prioritized the electrification of transportation, the decarbonization of industry, and the development of products that require less energy to make, last longer, and are fully recyclable. While this chapter reviews the current state of graphene
Advanced two-dimensional materials discovered in the last two decades are now being produced at scale and are contributing to a wide range of performance enhancements in engineering applications. The most well known of these novel materials is graphene, a nearly transparent nanomaterial comprising a single layer of bonded carbon atoms. In relative terms, it has the highest level of heat and electrical conductivity, protects against ultraviolet rays, and is the strongest material ever measured. These properties have made graphene an attractive potential material for a variety of applications, particularly for transportation-related uses, and especially for aerospace engineering. The goals of reducing greenhouse gas emissions and creating a world that achieves net-zero emissions have prioritized the electrification of transportation, the decarbonization of industry, and the development of products that require less energy to make, last longer, and are fully recyclable. These aspects have
Efficient and accurate ordinary differential equation (ODE) solvers are necessary for powertrain and vehicle dynamics modeling. However, current commercial ODE solvers can be financially prohibitive, leading to a need for accessible, effective, open-source ODE solvers designed for powertrain modeling. Rust is a compiled programming language that has the potential to be used for fast and easy-to-use powertrain models, given its exceptional computational performance, robust package ecosystem, and short time required for modelers to become proficient. However, of the three commonly used (>3,000 downloads) packages in Rust with ODE solver capabilities, only one has more than four numerical methods implemented, and none are designed specifically for modeling physical systems. Therefore, the goal of the Differential Equation System Solver (DESS) was to implement accurate ODE solvers in Rust designed for the component-based problems often seen in powertrain modeling. DESS is a text-based
A team of inventors from NASA Langley and NASA Ames have created a new type of carbon fiber polymer composite that has a high thermal conductivity. This was achieved by incorporating Pyrolytic Graphite Sheets (PGSs) and Carbon Nanotubes (CNTs), which enhance the material’s ability to transfer heat when compared to typical carbon fiber composites.
Friction stir welding (FSW) is a method of welding that creates a weld trail by pressing a non-consumable rotating tool with a profiled pin on the adjacent surfaces while moving transversely along the welding direction. The method was initially used with metals and alloys, but more recently, thermoplastic polymers have also been included in its application. Investigations on FSW of thermoplastic polymers made of nylon and High-density polythene (HDPE) are presented here. Weld characteristics that are like those of the base materials are attempted to be achieved. Because of their unique nature and thermal conductivity, thermoplastics FSW differs from that of metals. The use of thermoplastic materials with conventional FSW procedures presents numerous difficulties and is currently ineffective. On the weld characteristics of nylon and HDPE, statistical methods were utilized to study the impact of temperature, rotational speed, and transverse speed. Temperature is found to be the most
Corrosion control is always of concern to the designer of electronic enclosures. The use of EMI gaskets to provide shielding often creates requirements that are in conflict with ideal corrosion control. This SAE Aerospace Recommended Practice (ARP) presents a compatibility table (see Figure 1) which has as its objective a listing of metallic couples that are compatible from a corrosion aspect and which still maintain a low contact impedance.
The latest developments in composite materials are anticipated by green engineering. Materials must be eco-friendly, recyclable, biodegradable, and easy to decompose. Researchers are interested in utilizing natural fibres, fillers, and synthetic active ingredients. Natural fiber-polymer composites can specify certain mechanical properties but are hydrophilic and weak, so they rarely meet the needed thermal properties. Composite material selection depends on the application and the superior properties of the fibre/filler: banana fibre (BF), ice husk (RH) and multi-walled carbon nanotubes (MWCNT). In this research article, a brief discussion of the heat transfer mechanism of composites and the development of energy conduction equation are performed for hybrid natural polymer composite. The maximum thermal conductivity observed for 10BF/10RH/1MWCNT wt.% composite is 0.2694 W/mK. From ANSYS numerical simulation, the temperature distribution along the composite wall temperatures T1 to T8
With the evolving demand in the automobile industry for lightweight and sustainable components, the study of natural fiber composites has gained significance. Such fibers are economically efficient and offer advantageous weight-specific properties. Additionally, they are non-abrasive and environmentally degradable, marking them as viable alternatives to conventional automobile materials. This research emphasizes the flax-based composite, developed using the hand lay-up method and augmented with three distinct graphene nanofillers. The graphene fillers are categorized as large nanorods (dimensions 3-5 nm, lengths 150-300 nm), small nano threads (dimensions 6-12 nm, lengths under 50 nm), and spherical particulates (dimensions 29-39 nm). Reinforcement was consistently maintained at 2%, 4%, and 6% by weight. The results indicate that a 4 wt.% inclusion of spherical graphene nanoparticles is particularly effective in enhancing the ultimate tensile strength and fracture elongation of the
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