Browse Topic: Heat transfer

Items (3,353)
In recent decades, interest in alternative fuels has grown exponentially. Hydrogen has been researched as total or partial substitutes for gasoline in light vehicles, showing great potential. However, this fuel has unique characteristics and properties that can bring improvements or limitations in engine performance. Therefore, a quick analysis of the pressure and HRR curve can highlight changes in combustion and performance. To this end, the aim of this work is to develop a visual interface generated by MATLAB capable of showing the performance parameters of a spark ignition engine when using hydrogen as fuel, initially. This graphic interface is supported with a zero-dimensional model based on the Wiebe function and Woschni correlation to estimating the pressure and HRR values. The interface is designed to receive operating conditions and geometry of the engine, as well as combustion angles. From the information entered, it is possible to visualize mass fraction burned, heat transfer
Rincon, Alvaro Ferney AlgarraAlvarez, Carlos Eduardo CastillaOliveira Notório Ribeiro, Jéssica
Virtual reality (VR), Augmented Reality (AR) and Mixed reality (MR) are advanced engineering techniques that coalesces physical and digital world to showcase better perceiving. There are various complex physics which may not be feasible to visualize using conventional post processing methods. Various industrial experts are already exploring implementation of VR for product development. Traditional computational power is improving day-by-day with new additional features to reduce the discrepancy between test and CFD. There has been an increase in demand to replace actual tests with accurate simulation approaches. Post processing and data analysis are key to understand complex physics and resolving critical failure modes. Analysts spend a considerable amount of time analyzing results and provide directions, design changes and recommendations. There is a scope to utilize advanced features of VR, AR and MR in CFD post process to find out the root cause of any failures occurred with
Savitha, BhuduriSharma, Sachin
The average product development cycle spans 3-5 years, involving extensive virtual and physical testing of the machine. Advances in simulation tools have significantly enhanced our ability to identify product solutions early in the design phase. Tools like 1D KULI and Creo Flow Analysis (CFA) offer faster solutions in less time, thereby accelerating the product development cycle. Cooling systems are crucial components of off-highway tractor machines, directly affecting engine efficiency and overall machine functionality. An optimized cooling system ensures the engine operates within safe temperature ranges, preventing overheating and potential damage. Thus, designing an effective cooling system is a vital aspect of machine engineering. 3D Computational Fluid Dynamics (CFD) simulations are essential for evaluating cooling system performance. These high-fidelity simulations provide detailed insights into fluid flow and heat transfer, enabling engineers to predict and enhance cooling
Ukey, SnehalTirumala, BhaskarNukala, Ramakrishna
This numerical study investigates a spark-ignited, two-stroke engine employing uniflow scavenging, flathead cylinder head design, and an exhaust valve system to identify the optimal bore-to-stroke (B/S) ratio for maximizing brake efficiency at fixed displacement. A single-cylinder prototype engine was constructed, and its experimental data validated a 1D GT-SUITE simulation model. This validated model was then utilized to simulate a full-scale, 1.5-liter displacement, horizontally opposed four-cylinder engine with supercharger-assisted boosting, intended for small aircraft propulsion. The simulations explored a range of B/S ratios from undersquare (0.7) to oversquare (1.5), maintaining a consistent brake power output of 60 kW at 3000 rpm and lambda 0.9. Results showed that increasing the B/S ratio enhanced brake efficiency from 26.0% at B/S=0.7 to 27.0% at B/S=1.5, largely due to reduced frictional losses attributed to shorter stroke and lower piston speeds, decreased heat transfer
Zanchin, GuilhermeHausen, RobertoFagundez, Jean LuccaLanzanova, ThompsonMartins, Mario
Electricity is a fundamental necessity for individuals worldwide, serving as a force driving technological progress hitherto unimaginable. Electricity generation uses diverse methodologies based on available natural resources in a given geographic region. Conventional methods like thermal power from coal and natural gas, water-based hydropower, solar power from the sun, wind power, and nuclear power are used extensively, the former two being the dominant sources. The generation of nearly 70% of the world's electricity is estimated to be from thermal power plants; however, these operations lead to widespread environmental destruction, greenhouse emissions, and the occurrence of acid rain. Conventional thermal power plants run on the Rankine cycle principle of a boiler, a turbine, a condenser, and a pump. A similar method may be used in the Organic Rankine Cycle (ORC) with the use of solar energy, where heat is transferred to the working fluid in the boiler using a heat pipe, a passive
Deepan Kumar, SadhasivamKumar, VDhayaneethi, SivajiMahendran, MSaminathan, SathiskumarR, KarthickA, Vikasraj
The proton exchange membrane (PEM) water electrolyzer is an emerging technology to produce green hydrogen due to its compactness and producing high purity hydrogen. This study presents a numerical investigation on multiphase flow dynamics and heat transfer within the anode flow field of a PEM water electrolyzer. Two different channel configurations, i.e., rectangular, semi-circular are considered having same cross-sectional area while keeping the porous transport layer (PTL) thickness constant (which is within the commercially available ranges). Simulations are conducted for various oxygen generation rates and heat fluxes (corresponding to different current densities) and different inlet water flow rates. The effects of channel configurations on pressure drop, flow uniformity, and temperature distribution are illustrated pictorially and graphically. The impact of water flow rates and oxygen generation rates on phase distribution, pressure drop, and temperature profiles, particularly
Dash, Manoj KumarBansode PhD, Annasaheb
In automotive systems, efficient thermal management is essential for refining vehicle performance, enhancing passenger comfort, and reducing MAC Power Consumption. The performance of an air conditioning system is linked to the performance of its condenser, which in turn depends on critical parameters such as the opening area, radiator fan ability and shroud design sealing. The opening area decides the airflow rate through the condenser, directly affecting the heat exchange efficiency. A larger opening area typically allows for greater airflow, enhancing the condenser's ability to dissipate heat. The shroud, which guides the airflow through the condenser, plays a vital role in minimizing warm air recirculation. An optimally designed shroud can significantly improve the condenser's thermal performance by directing the airflow more effectively. Higher fan capacity can increase the airflow through the condenser, improving heat transfer rates. However, it is essential to balance fan
Nayak, Akashlingampelly, RajaprasadNeupane, ManojMittal, SachinKumar, MukeshUmbarkar, Shriganesh
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
P, Geetha
To address the thermal management challenges in lithium-ion batteries-which are associated with safety, real-world driving, and operating cycles, particularly at high discharge rates and in extreme ambient conditions-it is essential to maintain the battery temperature within its optimal range. This work introduces a novel hybrid Battery Thermal Management System (BTMS) that integrating a Phase Change Material (PCM) and air cooling with fins attached to air-channel in PCM side. Unlike conventional approaches that use standard rectangular fins, this study employs angular fins with varying dimensions to enhance heat dissipation. The hybrid system is designed to leverage the high latent heat storage capability of the PCM while ensuring efficient convective heat removal through air cooling. The airflow through the cooling channel accelerates heat dissipation from the PCM, thereby increasing its effectiveness. The angular fins are strategically positioned within the PCM section to enhance
Kalvankar, TejasLam, Prasanth Anand KumarAruri, Pranushaa
Thermal management is critical for modern vehicles, particularly for Zero Emission Vehicles (ZEVs), where maintaining optimal temperature ranges directly influences thermal system efficiency and vehicle range. Accurate prediction of underhood airflow behavior is essential for effective thermal management and also to estimate overall energy consumption by cooling system, with air-side dynamics playing a pivotal role in heat transfer over the heat exchangers of cooling package. Simulation tools like GT-Suite are indispensable for this purpose, enabling engineers to evaluate complex thermal interactions without the cost and time constraints of extensive physical testing. While 3D Computational Fluid Dynamics (CFD) models offer detailed insights into flow characteristics, they are computationally expensive and time consuming. In contrast, 1D models provide faster simulation times, making them ideal for system-level analysis and iterative design processes. However, 1D models inherently lack
Mutyala k, AkhilPudota, PraveenFaseel, IhsanGole, PranaliBashir, Murad
Automotive mobile air conditioning (MAC) systems rely on effective thermal insulation to maintain cabin comfort and energy efficiency. However, insulation materials degrade over time due to thermal cycling and environmental exposure, impacting overall system performance. This study investigates the effects of reducing insulation material density (GSM) in critical areas such as the engine firewall, plenum, roof and door panels on MAC system efficiency. A multi-disciplinary approach combining basic engineering calculations, frontloading CAE simulations and targeted experimental testing was employed. Initial calculations provided directional input for cabin heat load analysis, guiding early-stage design decisions. Simulation models were used to predict the impact of insulation reduction on cooling performance, energy consumption and component durability, reducing reliance on iterative physical testing. Experimental validation was then conducted selectively, focusing on critical areas to
Kulkarni, ShridharDeshmukh, GaneshJoshi, GauravNayakawadi, UttamShah, GeetJaybhay, Sambhaji
Thermal management of electric vehicle (EV) battery systems is critical for ensuring optimal performance, user safety, and battery longevity. Existing high-fidelity simulation methods provide detailed thermal profiles, but their computational intensity makes them inefficient for early design iterations or real-time assessments. This paper introduces a streamlined, physics-based one-dimensional transient thermal model coded in MATLAB for efficiently predicting battery temperature behavior under various driving cycles. The model integrates vehicle dynamics to estimate power demands, calculates battery current output and heat generation from electrochemical principles, and determines the battery temperature profile through a 1D conduction model connected to a thermal resistance network boundary condition that incorporates the effect of coolant heat capacity. The model achieved prediction errors below 1% when compared to analytical solutions for conditions of no heat generation and steady
Builes, IsabelMedina, MarioBachman, John Christopher
Hydrogen has been identified as a promising decarbonization fuel in internal combustion engine (ICE) applications in many areas including heavy-duty on- and off-road, power-generation, marine, etc. Hydrogen ICEs can achieve high power density and very low tailpipe emissions. However, there are challenges; designing systems for a gaseous fuel with its own specific mixing, burn rate and combustion control needs, which can differ from legacy products. Being able to determine the thermal distribution and temperatures of the power cylinder components has always been critical to the design and development of ICE. SAE-2023-01-1675 [1] presented an analytical FE-based tool, and validation using both FE and CFD methods for a Euro VI HD Diesel engine converted to operate on hydrogen gas using direct injection. In this study, updated methods and investigations are presented for Hydrogen ICE including applicability of the Woschni heat transfer correlation, use of CFD thermal wall functions and a
Bell, David J.Shapiro, EvgeniyTurquand d Auzay, CharlesHernandez, IgnacioHynous, JanKohutka, JiriOsborne, RichardPenning, RichardTomiska, Zbynek
Thermal or infrared signature management simulations of hybrid electric ground vehicles require modeling complex heat sources not present in traditional vehicles. Fast-running multi-physics simulations are necessary for efficiently and accurately capturing the contribution of these electrical drivetrain components to vehicle thermal signature. The infrared signature and heat transfer simulation tool, “Multi-Service Electro-optic Signature” (MuSES), is being updated to address these challenges by expanding its thermal-electrical simulation capabilities, provide a coupling interface to system zero- and one-dimensional modeling tools, and model three-dimensional air flow and its convection effects. These simulation capabilities are used to compare the infrared signatures of a tactical ground vehicle with a traditional powertrain to a hybrid electric version of the same vehicle and demonstrate a reduction in contrast while operating under electrically powered conditions of silent watch and
Patterson, StevenEdel, ZacharyPryor, JoshuaRynes, PeteTison, NathanKorivi, Vamshi
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
Duchaussoy, AmandineLorenzino, PabloFranklin, JackTzedaki, Maria
Electrified vehicle energy management plays a crucial role in the context of the European Green Deal by facilitating the transition toward sustainable mobility. The development of predictive and robust simulation tools is essential to implement and test different energy management strategies. This study aligns with this objective by presenting the development of an under-hood flows model designed for integration into a 1D vehicle simulator, which is used to perform vehicle simulations about longitudinal performances, energy consumption and range. Vehicle under-hood thermal management is inherently complex due to the interplay of internal flow dynamics and multiple heat transfer mechanisms. A purely 1D modeling approach lacks the spatial resolution required to capture detailed flow field characteristics, while a fully 3D CFD model is computationally prohibitive for scenarios requiring efficient simulations. To address this trade-off, a reduced-order model (ROM) approach is proposed. The
Miccio, StefanoGrattarola, FedericoBaratta, MirkoGiraudo, GabrieleFrezza, DavideBartolucci, Lorenzo
The internal combustion engine (ICE) is projected to remain the dominant technology in the transport sector over the short to medium term, and there exists significant potential for further improvements in fuel economy and emission reductions. One promising approach to enhancing the efficiency of spark ignition engines is the implementation of passive pre-chamber spark plugs. The primary advantages of pre-chamber-initiated combustion include the mitigation of knocking, an increase in in-cylinder turbulence, and a combustion process that is both faster and more stable compared to that achieved with conventional J-gap spark plugs. Additionally, the higher ignition energy provided by pre-chamber spark plugs enables operation under higher intake pressures, maintains similar exhaust gas recirculation rates, and supports leaner combustion conditions. These benefits are predominantly attributed to volumetric ignition via hot, reactive jets. However, the pre-chamber spark plug also presents
Korkmaz, MetinJuressen, Sven EricRößmann, DominikKapus, Paul E.Pino, Sandro
Turbocharging technique is a key technology for the development of hydrogen engines, allowing high lambda values to reach low NOx emissions. In ultra-lean mixture conditions, the thermal management of the lubricating oil and its cold condition becomes a crucial aspect that cannot be neglected. Accordingly, the impact of different lubricating oils and different lubricant thermal conditions is highlighted referring to the performance of a turbocharging system for automotive application. To this aim, an experimental campaign is conducted at the test bench for components of propulsion systems of the University of Genoa. Tests are performed on a turbocharger equipped with a variable geometry turbine under both steady and unsteady flow conditions, considering different positions of the turbine regulating device. A 4-cylinder engine head was coupled to the turbocharger in order to reproduce the pulsating flow related to the opening and closing of the engine valves. The influence of the
Marelli, SilviaUsai, VittorioCordalonga, Carla
BATSS project objective is to design a safe, effective and sustainable battery pack. To achieve this, the battery system (BS) will be mechanically, electrically and thermally optimized using cutting edge technology. Consequently, the battery system includes innovative 4695 cylindrical cells and advanced thermal management, carried out with the Miba FLEXCOOLER®. This work focuses on the BS thermal optimization using system simulation tools. First a simplified version of the BS is simulated with all physical phenomena involved in thermal behavior to identify first order parameters. It appears that various BS component and heat transfer can be neglected in comparison with the heat transfer due to cooling system. Then the simulation of the full battery system is conducted under nominal condition. Cooling system appears to be performant as it allows a controlled averaged temperature and very low cell-to-cell temperature variability. Finally, impact of both design and operating parameters is
Chevillard, StephanePopp, HartmutGalarza, IgorPetit, Martin
Battery management systems are among the key components in electric vehicles (EVs), which are increasingly replacing internal combustion engine (ICE) vehicles in the automotive industry. Battery management systems mainly focus on battery thermal management, efficiency, battery life and the safety conditions. Generally, lithium-ion batteries have been chosen in EV cars. Therefore, the internal resistance of Li-ion batteries plays a crucial role in the thermal behavior of the energy storage system. Most of the published studies rely on 0D-1D models to analyses single cell thermal behavior depending on the internal resistance at different ambient temperatures and charging/ discharging rates, and on the cooling system. However, these models, though fast, cannot provide detailed information about the temperature distribution within a cell or a module. Full 3D Computational Fluid Dynamics (CFD)- Conjugate Heat Transfer (CHT) simulations on the other hand, are very time consuming and require
Karaca, CemOlmeda, PabloMargot, XandraPostrioti, LucioBaldinelli, Giorgio
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
Gutierrez, MarcosTaco, DianaBösenhofer, Markus
Velocity and temperature distributions in a Close Coupled Catalyst (CCC) were analyzed using two identical Computational Fluid Dynamics (CFD) setups, differing only in inflow boundary conditions: one pulsating and the other constant. The objective was to assess the validity of the common simplification of assuming constant inflow. While several studies have addressed this question, they have focused exclusively on naturally aspirated engines. This study examines a CFD domain featuring a turbine - resulting in fundamentally different flow conditions reaching the CCC substrate. The results demonstrate that exhaust pulsations lead to a more uniform flow within the CCC at a lower temperature. These findings, supported by existing literature, suggest that the assumption of constant inflow should be critically evaluated rather than assumed by default.
Bergman, MiriamKlövmark, HenrikLaurell, Mats
Wankel rotary engines generally present an unfavourable surface area-to-volume ratio that prevents them from obtaining the high efficiency needed for the currently challenging applications in the mobility sector. In a previous study, an optimisation of Wankel engine geometry was carried out in order to minimise the surface area-to-volume ratio, with the aim of reducing the overall heat loss during the combustion phase. The study reported a counterintuitive finding that the minimum surface area-to-volume ratio configuration actually produced the worst heat loss due to the unusual flow field inside the combustion chamber affecting the Reynolds and Nusselt numbers. The present study aims to provide insights into the surprising results using a detailed flow and heat transfer analysis by undertaking detailed CFD simulations for the most representative configurations in the previous study. The CFD results confirmed the findings of the previous study, showing that the modified Woschni model
Vorraro, GiovanniIm, Hong G.Turner, James
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
Ahammed, SajidAhmad, ZeeshanMahmoudzadeh Andwari, AminKakoee, AlirezaHyvonen, JariMikulski, Maciej
Advancements in additive manufacturing (AM) technology have enabled the use of Triply Periodic Minimal Surface (TPMS) lattice structures to integrate thermal and structural functions into a single component. These structures offer advantages such as weight reduction, compactness and enhanced heat dissipation, making them promising for automotive, aerospace and electronics applications. TPMS structures, characterized by zero mean curvature and periodic crystalline geometry, have recently gained significant research attention thanks to their potential in thermal management. Among various TPMS geometries, the gyroid and diamond structures stand out for their thermal and fluid dynamic performance. This study explores the influence of cell geometry, unit cell size, and wall thickness on the efficiency of TPMS-based heat exchangers, as these parameters are crucial for their technical feasibility. Using Computational Fluid Dynamics (CFD) simulations, a comparative analysis is conducted for a
Cordisco, IlarioTorri, FedericoBerni, FabioTesta, VeronicaGiacalone, MauroFontanesi, Stefano
For further elucidation of the extremely complex mechanism of wall heat transfer during diesel flame impingement, heat flux measurement results based on two different relatively new approaches, high-speed infrared thermography and Micro Electro- Mechanical Systems (MEMS) heat flux sensor, were compared. Both measurements were conducted on the chamber wall impinged by a diesel flame achieved in constant volume combustion vessels under similar experimental conditions. Infrared thermography was conducted using a high-speed infrared camera (TELOPS M3k, 13,000 fps, 128×128 pixels), allowing the capture of time-series temperature and heat flux distributions on the wall surface with a spatial resolution of 70 μm (9 mm / 128 pixels). This high-resolution imaging also enables detailed estimation of near-wall turbulent structures, which are considered to significantly influence the heat flux distributions. The MEMS sensor is composed of closely aligned (520 microns separated) multiple highly
Shimizu, FumikaMorooka, MasatoAizawa, TetsuyaDejima, KazuhitoNakabeppu, Osamu
Decarbonizing the transport sector requires solutions that reduce CO₂ emissions while improving the efficiency of existing engine platforms. This study explores a retrofit strategy in which a heavy-duty diesel engine is converted to Otto-cycle operation and equipped with a passive pre-chamber combustion (PPCC) system. Methanol was used as the fuel due to its high octane number, low carbon intensity, and favourable combustion properties. The performance of the PPCC system is experimentally compared to conventional spark ignition (SI) across varying engine speeds, loads, and exhaust gas recirculation (EGR) levels. A dual-dilution strategy, combining lean operation (λ = 1.6) with EGR, was applied to extend dilution tolerance and assess the feasibility of operating near stoichiometry. All tests were conducted under steady-state conditions with fixed spark timing. Results show that PPCC consistently delivers faster combustion than SI across all conditions, with greater stability and reduced
Fong Cisneros, Eric J.Hlaing, PonnyaCenker, EmreAlRamadan, AbdullahTurner, James WG
Reactivity-controlled compression ignition (RCCI), a low-temperature combustion strategy, reduces oxides of nitrogen (NOx) and soot simultaneously; however, high concentrations of carbon monoxide (CO) and total hydrocarbons (THC) and low exhaust gas temperatures pose a significant challenge for the catalytic control of tailpipe CO and THC. Diesel oxidation catalyst (DOC) is generally used in compression ignition (CI) engines for CO, THC, and nitric oxide (NO) oxidation. This work provides a new understanding of the performance characteristics of a DOC in the RCCI combustion strategy with various gasoline–diesel fuel premix ratios ranging from ~46% to ~70% at steady-state operating conditions. Experimental insights from the RCCI strategy prompt considerations of both CO and THC oxidations and THC trap functionalities in the 1D transient model of the DOC. It is observed that an increase in the fuel premix ratio from 50% to 70% in RCCI shifts the CO and THC oxidation characteristics
Suman, AbhishekSarangi, Asish KumarHerreros, Jose Martin
By combining topology optimization and additive manufacturing, a team of University of Wisconsin-Madison engineers created a twisty high-temperature heat exchanger that outperformed a traditional straight channel design in heat transfer, power density and effectiveness.
Electrification of city busses is an important factor for decarbonisation of the public transport sector. Due to its strictly scheduled routes and regular idle times, the public transport sector is an ideal use case for battery electric vehicles (BEV). In this context, the thermal management has a high potential to decrease the energy demand or to increase the vehicles range. The thermal management of an electric city bus controls the thermal behaviour of the components of the powertrain, such as motor and inverters, as well as the conditioning of the battery system and the heating, ventilation, and air conditioning (HVAC) of the drivers’ front box and the passenger room. The focus of the research is the modelling of the thermal behaviour of the important components of an electric city bus in MATLAB/Simscape including real-world driving cycles and the thermal management. The heating of the components, geometry and behaviour of the cooling circuits as well as the different mechanisms of
Schäfer, HenrikMeywerk, MartinHellberg, Tobias
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
Mane, Pravin AshokDhawale, Pravin A.Nipanikar, SureshKhadtare, Avinash N.
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
Hopper, Elizabeth R.Williams, Megan S.Gahagan, Michael
Since proportion of wall heat loss takes as high as 20-30% of the total engine heat loss, the reduction of wall heat loss is considered as an effective way to improve the engine thermal efficiency. The heat transfer near the wall boundary layer plays a significant role on the exploration about the mechanism of wall heat transfer which contributes to figuring out the approach to the reduction of wall heat loss. However, the near wall characteristics of heat transfer are still unclear. In this study, the premixed lean methane flame propagation was captured by the high-speed schlieren and the flame behavior in the near-wall region was investigated by the micro CH* chemiluminescence. The temporal histories of the wall temperature and the heat flux are measured by the co-axial thermocouple. The factors including the convective heat transfer coefficient and non-dimensionless numbers, Nusselt number and Reynolds number, were used to characterize the near wall characteristics. Also, the
Xuefeng, XueRun, ChenTie, Li
The optimization of engine combustion systems based on scaled model experiments can reduce the cost of the development of large-bore marine diesel engines. Illustrating the transient heat transfer similarity of impinging flames would be beneficial to scaled engine model experiments in the development and optimization of large-bore compression ignition engines. In this work, the investigation of the similarity of the transient heat transfer of wall-impinging flames was performed in a high-pressure high-temperature constant-volume vessel. Two different injectors featuring different hole sizes and different flame impingement distances were applied to simulate the diesel spray impinging flames under the large-bore and the small-bore compression ignition engine-like conditions with a geometry similarity ratio equal to 0.7. By varying the injection parameters such as injection pressure and injection duration, the scaling laws based on constant injection pressure, constant engine speed, and
Cao, JialeLi, TieZhou, XinyiXu, XingyuChen, RunLi, ShiyanOgawa, Hideyuki
As the automotive sector shifts towards cleaner and more sustainable technologies, fuel cells and batteries have emerged as promising technologies with revolutionary potential. Hydrogen fuel cell vehicles offer faster refueling times, extended driving ranges, and reduced weight and space requirements compared to battery electric vehicles, making them highly appealing for future transportation applications. Despite these advantages, optimizing electrode structures and balancing various transport mechanisms are crucial for improving PEFCs’ performance for widespread commercial viability. Previous research has utilized topology optimization (TO) to identify optimal electrode structures and attempted to establish a connection between entropy generation and topographically optimized structures, aiming to strengthen TO numerical findings with a robust theoretical basis. However, existing studies have often neglected the coupling of transport phenomena. Typically, it is assumed that a single
Tep, Rotanak Visal SokLong, MenglyAlizadeh, MehrzadCharoen-amornkitt, PatcharawatSuzuki, TakahiroTsushima, Shohji
Thermal runaway in battery cells presents a critical safety concern, emphasizing the need for a thorough understanding of thermal behavior to enhance battery safety and performance. This study introduces a newly developed AutoLion 3D thermal runaway model, which builds on the earlier AutoLion 1D framework and offers significantly faster computational performance compared to traditional CFD models. The model is validated through simulations of the heat-wait-search mode of the Accelerating Rate Calorimeter (ARC), accurately predicting thermal runaway by matching experimental temperature profiles from peer-reviewed studies. Once validated, the model is employed to investigate the thermal behavior of 3D LFPO cells under controlled heating conditions, applying heat to one or more surfaces at a time while modeling heat transfer from non-heated surfaces. The primary objective is to understand how these localized heating patterns impact temperature profiles, including average core temperatures
Hariharan, DeivanayagamGundlapally, Santhosh
The drive unit of electric vehicles is a complex system consisting of an electric motor and a gear train, which work together to provide the necessary power for vehicle propulsion. One essential component within this system is the ball bearing, which supports the rotating components such as gears and shafts. This study focuses on the thermal simulation of a ball bearing within the drive unit conducted using the Volume of Fluid (VOF) method coupled with mixed timescale Conjugate Heat Transfer (CHT) in Simerics-MP+ to reduce the computational time while ensuring accuracy in the analysis. The Computational Fluid Dynamics (CFD) approach considers the geometrical details and clearances of the inner race, outer race, cage, and ball within the ball bearing. By accounting for the relative motions between these components, it can accurately model the film formation of the lubricating oil and its impact on heat removal from the bearing. The simulations are conducted at two different shaft speeds
Ballani, AbhishekMotin, AbdulDhar, SujanGanamet, AlainMaiti, DipakRanganathan, RajPandey, Ashutosh
Items per page:
1 – 50 of 3353