Browse Topic: Heat transfer

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Virtual Paint Shop: Automotive E-coating Process2026-26-0365To be published on 01/16/2026
The automotive paint shop is one of the most energy-intensive processes in vehicle manufacturing. This drives automotive OEMs to continuously improve production efficiency and reduce operational costs through digital twin technologies. Additionally, the push for shorter time-to-market emphasizes the need for simulation-based manufacturing processes—such as virtual testing and CAE simulations—to enable faster, data-driven decision-making early in the product development cycle, ultimately reducing cost and development time. Among the various stages in the paint shop, two of the most critical are: 1. Electro-dip coating (E-coating), also known as Electro-Deposition coating, which applies a corrosion-resistant primer to the Body-in-White (BIW). 2. Oven curing, which ensures the primer is properly bonded and cured for long-term protection and finish quality. To optimize these processes, a Dip-Drain-E-Coating simulation was developed using Siemens Simcenter STAR-CCM+. This simulation
Gundavarapu, V S Kumar, p, Vivekaanandan, Garg, Manish, Navelkar, Tanay, BS, Balachandran
Exhaust Hot end system Transient Heat Transfer Analysis using Heat Transfer Coefficient (HTC) approach, Thermo-Mechanical Fatigue Analysis to evaluate thermal durability and physical validation through Thermo-Shock Testing2026-26-0224To be published on 01/16/2026
Exhaust system suppliers are continuously enhancing their processes by adopting advanced simulation techniques and expedited testing procedures for optimizing exhaust systems. This aims to reduce time to market, accelerate vehicle launches, and ensure first-time right and consistent compliance with performance and durability standards. Traditionally, the CFD team conducts Conjugate Heat Transfer (CHT) analysis on the exhaust hot end system using input conditions such as engine-out gas temperature and maximum mass flow rate. The CAE team then performs steady-state heat transfer analysis by sharing the structural CAE model with CFD for CHT skin temperature mapping. Once steady state heat transfer analysis complete, skin temperature plots are to be compared with CFD to match CHT temperature results. These results are used for steady-state thermo-mechanical analysis across all heat-up cycles and assume system under ambient temperature for all cool-down cycles to evaluate system thermal
Natarajan, Suresh, J Y, Raja Shangara Vel
System Level Temperature Distribution and Balancing in battery swapping stations2026-26-0361To be published on 01/16/2026
Battery charging systems generate heat during operation, which affects battery efficiency, discharge time, and overall lifespan. Effective thermal management is essential to prevent overheating, optimize heat dissipation, and ensure consistent performance. This study investigates testing methodologies to analyse thermal temperature distribution, detect imbalances, and implement effective balancings techniques. Testing was conducted in a controlled environmental chamber to evaluate heat dissipation behavior under varying conditions. Different dock-level temperatures were measured and optimized using multiple design configurations to assess their impact on thermal performance. The analysis identified thermal imbalances that contribute to uneven heat distribution and increased thermal stress, which can degrade battery performance over time. By refining system designs and incorporating optimized balancing strategies, the research demonstrated significant improvements in heat management
Kulkarni, Mukund, P, Hari Prasad Reddy, H, Manjunatha, Dash, Soumya
Optimization and Evaluation of Thermal Interface Material Thickness and Distribution Patterns for Improved Heat Transfer in Liquid-Cooled Battery Pack2026-26-0432To be published on 01/16/2026
Battery Thermal Management Systems (BTMS) play a critical role in ensuring the longevity, safety, and efficient operation of lithium-ion battery packs. These systems are designed to effectively dissipate the heat generated by the cells during vehicle operation, thereby maintaining a uniform temperature distribution across the battery modules, preventing overheating and mitigating the risk of thermal runaway. However, one of the primary challenges in BTMS design lies in achieving effective thermal contact between the battery cells and the cooling plate. Non-uniform or excessive application of Thermal Interface Materials (TIMs) without ensuring robustness and uniformity can increase interfacial thermal resistance, leading to significant temperature variations across the battery modules, which may trigger power limitations via the Battery Management System (BMS) and these thermal gradients can cause inefficient cooling, ultimately affecting battery performance and lifespan. In this study
K, Mathankumar, Jahagirdar, Manasi, Kumbhar, Makarand Shivaji
Numerical Analysis of Rear Windshield Deicing with Heating Wires2026-26-0373To be published on 01/16/2026
Motivation: Windshield deicing is a crucial safety feature in vehicles, typically associated with the front windshield. However, the rear windshield also plays a significant role in ensuring safety and needs to be clear. Deicing of the front windshield is usually done using the hot air nozzle from the HVAC system. Modern rear windshields are equipped with heating wires that generate heat upon electrical supply to facilitate deicing. However, excessive use of these heating wires can lead to unnecessary energy consumption, impacting the vehicle's overall efficiency. This is the key motivation behind the development of an optimized heating system for the rear windshield. Problem: Design an optimized heating system for rear windshields that balances effective deicing with minimal energy usage, enhancing both safety and energy efficiency in vehicles. Methodology: This paper explores the numerical application of heating methods using CFD software to deice the rear windshield. The study
Kumaravel, Rajarajeshwari, Ibrahim, Sayyaf, Mathew, Ronnie
Cabin Heat-up Thermal Assessment for Human Comfort in Passenger Car2026-26-0408To be published on 01/16/2026
The HVAC (Heating, Ventilation and Air conditioning) system is designed to fulfil the thermal comfort requirement inside vehicle cabin. Thermal comfort is significantly subjective which predominantly dependent on occupant’s physiological condition. Vehicle AC performance is evaluated by air flow and local temperature thus, thermal comfort assessment is carried out by mapping of velocity and temperature at various places inside cabin. There is need to have Simulation methodology for heating cabin during cold climate to assess ventilation system effectiveness. Thermal comfort modelling involves human manikin, complex cabin material along with environmental condition in expensive transient simulation. Present study employed with LBM (Lattice-Boltzmann Method) based PowerFLOW solver coupled with finite element based PowerTHERM solver to simulate the cold soaking and heating up of cabin. Thermal comfort is subjective to human physiological modelling thus in-built Berkeley human comfort
Baghel, Devesh Kumar, Kandekar, Ambadas, Kumar, Ravi, Dimble, Nilesh
Evaluation of Intercooler Effectiveness with No Fan, Single Fan, and Dual Fan: A Simulation and Experimental Study2026-26-0579To be published on 01/16/2026
Turbochargers play a crucial role in modern engines by increasing power output and fuel efficiency through intake air compression, thereby improving volumetric efficiency by allowing more air mass into the combustion chamber. However, this process also raises the intake air temperature, which can reduce charge density, lead to detonation, and create emissions challenges-such as smoke limits in diesel engines and knock in gasoline spark-ignited (GSL) engines. To mitigate this, intercoolers are used to cool the compressed air. Due to packaging constraints, intercoolers are typically long and boxy, limiting their effectiveness, especially at low vehicle speeds where ram air flow is minimal. This study investigates the use of auxiliary fans to enhance intercooler performance. Two methodologies were adopted: 1D simulation using GT-Suite and experimental testing on a vehicle under different fan configurations-no fan, single fan, and dual fans (positioned near the intercooler inlet and outlet
PATRA, SOMNATH, HIBARE, NIKHIL, Ganesan, Thanigaivel, Gharte, Jignesh Rajendra
Development of Advanced Thermoplastic Elastomeric Mat and Its Study on Thermal Performance of Wireless Charging System2026-26-0283To be published on 01/16/2026
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
NAIKWADI, AMOL TARACHAND, Mali, Manoj, Patil, Bhushan, Tata, Srikanth
Evaluation of Thermo-Mechanical behavior of brake discs in vehicles using Multidisciplinary approach2026-26-0433To be published on 01/16/2026
The objective of this paper is to evaluate the thermal performance of the brake discs in the design stage of its life cycle by developing a methodology to replicate the dynamometer testing using multi-disciplinary Finite Element Analysis (FEA) methods. A simulation workflow was formulated in which Computational Fluid Dynamics (CFD) was used to create temperature and velocity dependent Heat Transfer Coefficients (HTC) which were in turn used in Computer Aided Engineering (CAE) to do a thermo-mechanical analysis. With this workflow various designs of the brake discs were analyzed. A sensitivity study was done to determine critical design features that affected its thermal performance. A final design was fixed that met both the weight and thermal performance targets. This design was evaluated in dynamometer testing, and 95% correlation was achieved. Thus, the developed simulation workflow ensured that a first-time right brake disc can be finalized in the design stage, which will meet the
Balaji, Praveen, K, Karthikeyan, S, KESAVPRASAD, S Kangde, Suhas
Simulation Based Approach to Optimize Electric Vehicle Battery Thermal System2026-26-0376To be published on 01/16/2026
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 can enhance these techniques during early product development and life cycle. In this work, a method to optimize the battery thermal system comprising of cooling plate and external insulation is described. The first part is to optimize the cell heat extraction by the cooling plate. The heat transfer coefficient of the coolant is a parameter which can indicate the thermal efficiency of a cooling plate. At the same time, it's important to keep the coolant pressure drop within a reasonable limit. A 1D simulation methodology is described to optimize the cooling channel height based on pressure drop and heat transfer coefficient targets. This methodology is based on empirical correlations and multi-objective pareto optimization. The advantage of
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 Packs.2026-26-0474To be published on 01/16/2026
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 with selecting the cross-sectional area based on current-carrying capacity and material type. The width matches or exceeds the battery cell terminal size, while the length is optimized based on space constraints. The research also highlights the risk of busbars to oxidation and corrosion, which increases resistance and decreases thermal conductivity for which Plating and coating techniques are applied to improve surface hardness, durability, and thermal conductivity while minimizing heat loss. Using simulations and experimental validation, the study examines three key design parameters: weld diameter, electrical resistance, and contact resistance. A detailed analysis investigates how weld diameter influences electrical resistance and temperature rise, as well as the impact of contact resistance between
Nogdhe, Yogesh, Singh, Shobit Kumar, Paul, Jibin, Mishra, Mukesh, MENON, Praveen
Advanced Thermal Management for High-Tonnage EVs: Increasing Coolant Flow and Reducing Energy Losses2026-26-0196To be published on 01/16/2026
With the increasing tonnage of electric heavy commercial vehicles, there is a growing demand for higher power and torque-rated traction motors. As motor ratings increase, efficient cooling of the EV powertrain system becomes critical to maintaining optimal performance. Higher heat loads from traction motors and inverters pose significant challenges, necessitating an innovative cooling strategy to enhance system efficiency, sustainability, and reliability. Battery-electric heavy commercial vehicles face substantial cooling challenges due to the high-pressure drop characteristics of conventional traction system cooling architectures. These limitations restrict coolant flow through key powertrain components and the radiator, reducing heat dissipation efficiency and constraining the operating ambient temperature range. Inefficient cooling also leads to increased energy consumption, impacting the overall sustainability of electric mobility solutions. This paper presents a novel approach to
DIXIT, SAMEER, Patil, Bhushan, Ghosh, Sandeep
Evaluating Thermal Control Strategies to Improve Electric Vehicle Range Using GT Suite2026-26-0362To be published on 01/16/2026
This study focuses on enhancing energy efficiency in electric vehicle (EV) thermal management systems through the development and optimization of control logic. A full vehicle thermal management system (VTMS) was modeled using GT-Suite software, incorporating sub-systems such as the high-voltage battery (HVB), e-powertrain (EPT), and an 8-zone cabin. Thermal models were validated with experimental data to ensure accurate representation of key dynamics, including coolant-to-cell heat transfer, cell-to-ambient heat dissipation, and internal heat generation. Control strategies were devised for Active Grille Shutter (AGS) and radiator fan operations, targeting both cabin cooling and e-powertrain thermal regulation. Energy consumption was optimized by balancing aerodynamic drag, fan power, and compressor power across various driving conditions. A novel series cooling logic was also developed to improve HVB thermal management during mild ambient conditions. Simulation results demonstrate
Chothave, Abhijeet, Kumar, Dipesh, Gummadi, Gopakishore, Khan, Parvej, Thiyagarajan, Rajesh, Pandey, Rishabh, S, Ananth, Anugu, Anil, Mulamalla, Sarveshwar, Gangwar, Adarsh
Development and Validation of Feet Thermal Comfort in Very Cold Climate with high fidelity to capture a transient heat transfer phenomenon2026-26-0406To be published on 01/16/2026
Customer Centric approach drives the automotive industry to focus on providing adequate cabin thermal comfort in cold & very cold environments. The quotidian life of a driver from countries in the northern hemisphere faces the issue of cabin temperatures plummeting below 0 deg C in winter. This permeates the passengers and leads to serious conditions like frostbite and hypothermia with prolonged exposure. Transient Validation of Thermal Comfort for 'Customer-centric Heating cycles' replicating regular commute (1 hour) from Home-to-Office is set as target for transient method development in FLUENT & CCM+. This precludes the requirement of comfort achievement with transient targets with high fidelity in HVAC, Stratification of flow through ducts, Material strategies in cabin, positioning of vents, optimum distance between vent to head/feet and furthermore. This paper explicates the thermal and flow behavior of Hot air from lower ducts toward front driver and front-rear passengers and
Saravanan, Vivek, Mathew, Viju, Colibert, Lionel, Perumalsamy, Jidhesh, Sarapalli Ramachandran, Raghuveeran, Athithan, Rajamani
3D Transient CHT Simulation of Frictional Heating in Jet-Lubricated Automotive Gears2026-26-0468To be published on 01/16/2026
Gears play a critical role in automotive transmission systems. During operation, frictional heat is generated in the intermeshing region due to loading. Effective lubrication and cooling are essential to minimize heat generation and ensure smooth operation. Lubrication failure can lead to a significant local temperature rise, potentially causing gear scuffing—a phenomenon where intermeshed gear teeth weld together and tear apart during rotation—resulting in severe damage and compromised transmission performance. To prevent this, gears are typically lubricated using splash or jet lubrication techniques. This study presents a Conjugate Heat Transfer (CHT) simulation of a jet-lubricated gear pair in an automotive transmission system to predict the local temperature rise due to frictional heating in the intermeshing region of the gears. The paper focuses on implementation of the frictional heat generation on the gear teeth and resultant transient temperature rise in the gear contact region
Ballani, Abhishek, Pasunurthi, Shyam Sundar
Performance Analysis of Graphene-Coated Heat Pipe Heat Exchangers for Automobile Exhaust Cooling and Purification2025-01-500601/23/2025
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
Karthigairajan, M., Seeniappan, Kaliappan, Balaji, N., Natrayan, L., Sheik, Salman Basha, Ravi, D.
Analyses of Cold Thermal Energy Storage Systems Using Eutectic Mixtures of Inorganic Hydrated Salts as Phase Change Materials2025-01-500301/23/2025
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
Vasanthkumar, P., Santhoshkumar, A., Gopika, P., Murali, M., Meera, C.
Numerical analyses of Ad-Blue thawing performance according to EU Norms2024-26-026301/16/2024
Controlling NOx emission demands is getting more serious with Euro 7 legislation. This in turn brings more focus on SCR (Selective Catalytic Reduction) technologies which uses a eutectic mixture of Urea (67.5%) - Water (32.5%) solution more popularly known as Diesel Exhaust Fluid (DEF/Ad-Blue). Under extreme winter conditions, Ad-Blue freezes as ambient reaches well below the freezing point (-11 deg.C). Due to Legislation requirement (EU), it is a matter of interest to estimate the time required by Ad-Blue to melt the desired volume inside the tank thereby defining overall Melting/Thawing performance. So far, testing has been the primary method for arriving at right melting mechanism and for designing electrical coils or hot coolant lines which is expensive. This paper proposes a novel digital method using 3D CFD tool STAR CCM+ to study the melting behavior of Ad-Blue. The method is characterized by capturing phase change using the popular multiphase (VOF) approach and different modes
GOVINDARAJAN, Vaishali, VARUGHESE, Shibu, Banik, Soumendu, R, Vineeth
Thermal Performance Prediction of Roots blower Using Coupled 3-D Multiphase CFD Thermal simulation with Experimental Validation2024-26-029701/16/2024
Abstract Roots blower is a rotary positive displacement pump which operates by pumping a fluid with a pair of meshing lobes. Recent trends in automotive industry demands high power density solutions for various applications. In comparison with legacy applications, compressors for high power dense applications demands more continuous operation with harsher duty cycle, demanding higher pressure ratios. Because of longer duty cycles, it will be subjected to high heat loads which will cause a rise in temperatures of timing gears, bearings, and other components within assembly. Accurate prediction of thermal performance is critical to design a durable and efficient roots blower for high power density applications. Thermal analysis of an assembly of roots blower involves modelling of multi-physics. This paper details a coupled CFD analysis approach to predict temperatures of roots blower components and timing gear case oil. Timing gears are lubricated using wet sump lubrication. The oil
C, Anandha krishnan, Jambare, Giridhar, Raut, Nikhil, Niranjan, Bhanupratap
Optimization of Cooling Air Flow for improved Heat Dissipation through Radiator.2024-26-004201/16/2024
Optimization of Cooling Airflow for improved Heat Dissipation through Radiator Authors: Paurnima Thakur, Amit Aher, Vishal Chavan, Chandrakant Palve Mercedes-Benz Research and Development India Private Limited Key Words: Radiator, Temperature, Heat Dissipation, Airflow, Cooling, Thermal Efficiency Abstract: Heat regulation is indispensable factor during operation of internal combustion engine. Automotive engine cooling system takes care of excess heat produced during engine operation. It regulates Engine surface temperature for engine optimum efficiency and plays important role in meeting CO2 emission target set by Environmental Protection Agency (EPA). Insufficient heat dissipation results into Engine overheating. This will affects thermal efficiency & ultimately brake specific fuel consumption of the Internal Combustion Engine. Radiator is the central component of a vehicle cooling system to monitor and regulate engine temperature and prevent it from overheating. Heat dissipation
Palve, Chandrakant, Thakur, Paurnima, Chavan, Vishal, Aher, Amit
Design Optimization and Thermal Simulation of a Plate Type Heat Exchanger (“Chiller”) for EVs Applications2022-28-044111/09/2022
The rapid evolution of electric vehicles (EVs) has considerably forced the automotive industry to design compact & highly efficient heat exchangers due to lower temperature applications. The plate type heat exchangers (Also known as "Chillers" in automotive industry) are one of the most important components in EVs thermal management systems. It is a type of heat exchanger, which uses metallic plates arranged like a staggered sandwiched structure to exchange heat between two working fluids. The heat transfer between the plates occurs due to highly compact structural design as compare to any conventional heat exchangers. The chiller is having very large surface area, which is exposed to the working fluids as the distribution happens all across the plates. The chillers are more suitable design for transferring heat between ranges of working fluids pressure varying from low to high pressures. Various types of welded, semi-welded plate heat exchangers are available. The working fluids flow
Suman, Saurabh, Kushwah, Yogendra Singh, SHUKLA, ANKIT, Singh, Shobhit Kumar
To Develop the model for heat transfer coefficient with Machine Learning Techniques.2022-26-123505/26/2022
Being the Need of Increasing the heat transfer for domain which under heat stress index,key parameter is heat transfer coefficient, Which majorly depends upon the float rate of the context, the input of the heating element which ultimately decide the the time of contact of fluid which raise the concern about heat transfer. The Main goal of the presented study is to Investigate and develope model for the heat transfer coefficient in forced convection.The study comprising two section as conduction the experiment by considering the parameters like air flow, heater input, varying one at a time, which will creat the dataset, with dependent label as heat transfer coefficient using empirical relation. Three Machine learning algorithm i.e is Support Vector Machines, Decision Tree and XG boost are tested over the dataset. The metrics like Root mean squre error and Mean absolute error is plooed with the doamin, All algorithm implemented with the Python.
Dorwat, Ajit L., Dhotre, Sanchit, Biradar, Ashish, Lokhande, Pravin
Non-parametric Optimization of Heat Sinks for Power Dense Motor Controllers2022-26-117505/26/2022
With the future of mobility moving towards electrification there is an ever-increasing demand in both aerospace and automotive industry for achieving higher power density in inverters, controllers, etc. In the aviation industry, the trend of more electric aircraft has resulted in transition from central to zonal architecture. In zonal architecture, controller units are kept close to the actuator systems and localized harsh bay conditions, space constraints coupled with the necessity for high power density has made thermal management a challenging task. This warrants a need for exploring innovative cooling techniques to manage the dissipated heat. This paper focuses on a liquid cooled thermal management system for power dense applications. The heatsink design presented here is a pin fin arrangement staggered to induce swirling flow, which has been proven to enhance heat transfer. The traditional heatsink optimization involves creating a design of experiments (DoE) with parameters like
Bhardwaj, Divyanshu, Datta, Sauradeep, Borkar, Kishor
Machine learning assisted analysis of heat transfer characteristics of a heavy duty natural gas engine2022-01-057203/29/2022
Heat transfer affects engine performance, efficiency, and emissions. Hence, it was essential to investigate the heat transfer characteristics after converting a compression ignition engine to a spark ignition and natural gas. The heat transfer for each engine speed and load was calculated based on Woschni’s correlation. As the number of experiments that provided engine response was limited, an artificial neural network approach was proposed to predict the engine heat transfer characteristics and aid in the analysis. The good agreement between the experimental results and data predicted by the machine learning algorithm validated the predictive capability of the artificial neural network model. The results of the data-driven analyses suggested that the heat transfer increased as the spark timing advanced. Moreover, increasing the engine speed reduced the heat flux form the combustion chamber to the engine coolant. Further, leaning the mixture lowered the heat transfer rate to the
Liu, Jinlong, Dumitrescu, Cosmin, Ulishney, Christopher
Engine Thermodynamic Design, Optimization, Test & Analysis of Daimler SuperTruck2 Program Towards 55% BTE Target2022-01-050403/29/2022
Daimler's effort toward demonstration of 55% brake thermal efficiency for the US Department of Energy SuperTruck2 program relied on a holistic approach to optimization of the Daimler heavy-duty 12.8L diesel engine. Core technical approaches used in this effort include efficient two-stage turbocharging with intercooling, valve timing optimization, improved combustion system design, friction and parasitics reduction through optimized lubrication system, and in-cylinder heat transfer reduction. These measures in combination provided an anticipated engine efficiency of over 50% BTE before application of an additional waste heat recovery system. Utilization of high-fidelity simulations from 1D physical model simulation studies and CFD/FEA framework allowed for optimization of the engine pumping loop and heat transfer reduction efforts. Test bench data provides high-level overview of combustion improvement, friction & parasitics reduction, improvement in in-cylinder heat transfer reduction
Bashir, Murad
Heat Transfer Analysis of an Electric Motor Cooled by a Large Number of Oil Sprays Using Computational Fluid Dynamics2022-01-023703/29/2022
This paper reports on an analytical study of the heat transfer and fluid flow in an electric vehicle e-Motor cooled by twenty five sprays/jets of oil. A three-dimensional, steady state, multi-phase, computational fluid dynamics (CFD) and conjugate heat transfer (CHT) model was created using a commercial CFD software. The transport equations of mass, momentum, energy and volume fraction were solved together with models for turbulence and wall treatment. An explicit formulation of the volume of fluid (VOF) technique was used to simulate the sprays, a time-implicit formulation was used for the flow-field and three dimensional conduction heat transfer with non-isotropic thermal conductivities was used to simulate the heat transfer in the windings. An important challenge was to formulate an efficient solution algorithm that can rigorously comprehend twenty five sprays in order to accurately predict the temperature distributions in the windings, without thrifting physics, and within
Srinivasan, Chiranth, Wan, Jingyi, Saha, Rohit, DHAR, Sujan, Paciura, Krzysztof, Nichani, Varun, Ranganathan, Raj
An experimental study of heat loss and spatially temperature distributions of the impinging plate2022-01-060703/29/2022
Spray impingement tends to occur in compact-size engines and it affects the fuel-air mixing, local heat transfer between fluid and solid, and possibly leads to fuel deposition on the hard surface. The deposits which are typically called “film” become one of the main sources of soot particles generated in the subsequent combustion. Wall temperature is one of the factors that affect fuel deposition. A higher wall temperature would enhance the film evaporation and reduces the risks of fuel deposition to partially avoid the soot particles formed from the film. Also, the wall temperature would affect the ignition characteristics such as ignition delay and ignition location. However, in realistic operating engines, the wall temperature is not consistent but changed by the heat conduction from charge gas and heat convection when the spray hits the wall and propagates near the surface. Due to the arrangement of injectors in the engines, an oblique injection is typically observed. This scenario
Zhao, Zhihao, Lee, Seong-Young
Research on Heat Dissipation Performance of Automobile Motor Based on Heat Pipe Optimization Design2022-01-088403/29/2022
In new energy vehicles, the electric motor, as the main power source, is developing toward high power density. However, its heat generation problem always affects the overall performance of the motor, so an efficient motor cooling system is especially important. In desert or water-scarce areas, liquid cooling cannot meet the needs of new energy vehicle motor cooling. When glycol or other liquid coolants are low or depleted, motor heat dissipation becomes less effective. Heat pipe is a heat dissipation technology with advantages such as fast thermal response and light weight. In this paper, by improving the heat pipe arrangement and reducing the overall mass of the heat dissipation system, a heat pipe optimization design based on a drive motor heat dissipation scheme is proposed, and the overall stability of the motor working under high temperature conditions is improved. In this paper, the heat pipe arrangement scheme is set up with the heat pipe heat transfer characteristics, and the
Yang, Chunyun
The Rotating Liner Engine under Medium Loads and Speeds. Fuel economy benefit exceeds 10%2022-01-050703/29/2022
The Rotating Liner Engine (RLE) is a design concept where the cylinder liner of a Heavy Duty Diesel engine rotates by about 2-4 m/s surface speed in order to eliminate the piston ring and skirt boundary friction near top and bottom dead center. Based on testing results from our single cylinder RLE prototype (a converted four cylinder Cummins ISB 3.9 diesel) compared to a similar baseline, under idle conditions, the friction reduction is approximately 50 kPa in FMEP (friction mean effective pressure), which translates to about 40% for a complete engine. In this new set of experiments, we are comparing the RLE performance under load of up to about 7 bar IMEP (indicated mean effective pressure). It has been proven that the elimination of metallic contact between the compression rings and cylinder persists under up to 75 bar peak cylinder pressure and 1.5-2 m/s liner surface speed (283-383 rpm) for the 850-1150 rpm crankshaft speed. Additionally, the RLE FMEP is substantially reduced under
Dardalis, Dimitrios, ALHAJ ASAD, Osama, Basu, Amiyo, Hall, Matthew, Matthews, Ron
Simulation of 2-Stroke D-Cycle Engine Concept for Agricultural Tractor2022-01-046403/29/2022
This paper explains to modify conventional 4-Stroke 2.7L 4-Cylinder CRS (Common Rail System) Naturally aspirated (NA) Diesel engine into 2-Stroke D-Cycle (i.e. Differential Stroke) engine for Agricultural Tractor applications. 1D Performance simulation was performed using GT-POWER to focus on how to maximize the combustion efficiency and power/torque demand using a 2-stroke D-Cycle by taking advantages of deficits in a 4-stroke engine, optimizing for improving emissions and realizing higher torque demands for Tractor field applications. Furthermore, appropriate cam geometries ensuing specific application of puddling, tillage etc. are generated which can be accommodated without major design changes. Exhaust, heat transfer, pumping, frictional losses, and volumetric efficiency are analyzed. Performance Simulation results shows that Fuel economy improvement of ~ 10%, average increase in Power output of ~ 30%, average NOx emission reduction of ~ 15% and better drivability at low engine
S, SHANKAR, Paulraj, Lemuel
Analysis of energy and exergy distribution for improving fuel economy of marine low-speed two-stroke diesel engine2022-01-046303/29/2022
Increasingly strict emission regulations and unfavorable economic climate bring severe challenges to energy conservation of marine low-speed engine. Besides traditional methods, the energy and exergy analysis could acknowledge the losses of fuel energy from a global perspective to further improve the engine economy. Therefore, in this study, a thermodynamic model is built based on experimental data to conduct the energy and exergy analysis for marine low-speed engine. Results of energy analysis shows that the exhaust gas accounts for the highest proportion of energy losses, and it rises with the increment of engine load. The proportion from heat transfer is just after the exhaust gas. But, it is negatively correlated to engine load. The energy analysis results indicate that reducing the proportions of exhaust gas and heat transfer is the best way to improve the fuel economy of engine. However, the exergy analysis demonstrates that there is still another more effective approach to
Zhang, Heng, Deng PhD, Kangyao, Wang, Dawei, LONG, Wuqiang, Qian, Yuehua
Impact of the vehicle environment on the thermal behavior of the electrical wiring2022-01-015403/29/2022
The thermal behavior of wires within the electrical distribution system (EDS) has a strong impact on the conductor cross section, the type of insulation, the derating and the fusing system, and therefore on weight, cost, and reliability. Consequently, significant efforts have been made to develop sound static and dynamic thermal models for single wires and wire bundles. However, these models are based on the simplifying assumption that the object is completely surrounded by air, where, with the exception of internal convection, airflow can be neglected, and where no interaction with other objects is considered. The approach presented in this paper takes into account the real environment and routing within a vehicle, where some objects such as metal sheets can be considered as heat sinks and other objects, e.g. a motor block, as heat sources. For this reason, measurements were performed using an experimental set-up that allows any desired positioning and alignment of the DuT (device
Brabetz, Ludwig, Ayeb, Mohamed, Koppe, Christian, Hesse PhD, Benjamin
Use of Thermally Conductive Electrically Insulative (TCEI) Materials in E-motor Slot Liner Applications2022-01-022403/29/2022
Slot liners are commonly used in electric motors to electrically insulate the motor windings from the laminated core. However, thermal conductivity of materials commonly used as slot liners is very low compared to other components in the motor thus creating a barrier for heat transfer. This thermal barrier affects overall motor performance and efficiency. Also, slot liners typically lack intimate contact with the laminated core resulting in air gaps which further increase thermal resistance in the system. Slot liners are traditionally made from high temperature films/papers that are cut and slid into slots of motors. The proposed work looks at developing an injection moldable slot liner to minimize air gaps. Additionally, use of TECI materials further lowers thermal resistance. A thermal finite element model has been developed to evaluate effects of slot liner thermal properties and air gaps on temperature distribution within the motor. The model incorporates varying material
Sundararaman, Saikrishna, Szparagowski, Ray
Multiple Heat Exchangers for Automotive Systems – A Design Tool2022-01-020503/29/2022
A single radiator cooling system architecture has been widely applied in ground vehicles for safe equipment (e.g., engine block, electronics, and motors) temperature control. The introduction of multiple smaller heat exchangers provides additional energy management features and alternate pathways for continued operation in case of critical subsystem failure. Although cooling performance is often designed for maximum thermal loads, systems typically operate at a fraction of the peak values for most of their life cycle. In this project, a two-radiator configuration with variable flow rates and valve positions has been mathematically modelled and experimentally validated to study its performance feasibility. A multi-node resistance-capacitance thermal model was derived using the ε-NTU approach with accompanying convective and conductive heat transfer pathways within the system. This engineering model provides an analytical description of the system behavior that can be leveraged for
Syed, Zaker, Miller, Richard, Wagner, John
Thermal Design and Performance of Airplane In-Flight Food Storage CarsARP8058A (Current)11/09/2021
This SAE Aerospace Recommended Practice (ARP) provides design guidance and a method for testing thermal performance of airplane in-flight food storage carts. It is noted that thermal performance criteria is not part of AS8056.
S-9B Cabin Interiors and Furnishings Committee
Decoding Genuine Ceramic Pad Formulations- Materials and Processing2021-01-127710/11/2021
The need to develop genuine ceramic composites for PV applications arose to overcome the challenges associated with traditional semi-metallic pads. The main focus is to achieve better performance, low noise, better pad and rotor wear, and low dust compared to semi- metallic pads. In general, brake pads convert kinetic energy to thermal energy through friction, and operating temperature in semi-metallic brake pads is higher due to the presence of steel having high thermal conductivity. Over the last decade, the customer preference has moved over to ceramic pads due to light coloured pad surface, low rotor and pad wear and low dust compared to semi-metallic pads. The traditional steel has been replaced by Aramid, engineered ceramic fibre, potassium titanate (TISMO D), lapinus fibre (RB 250) to impart similar/better performance. The current work investigates the characterisation of genuine ceramic and semi-metallic composites. Three genuine ceramic and one semi-met composite have been
Tomar, Bharat, Ali, Sharafat, Ellis, Keith, Choudhary, Yogesh
A Molecular Dynamics Study of Tribological Properties of Silicon Carbide as a Metal-Free Friction Material2021-01-128410/11/2021
Friction materials containing metal ingredients used in the automotive industry can cause unfavorable environmental impacts. Existing laws and regulations require heavy metals in brake pads to be phased out of production. Substitutions for metals in friction materials, however, may introduce operational safety issue and other unforeseen problems. In the current study, a molecular dynamics model based on LAMMPS has been developed to study the effect of material composition, density, and geometric configurations on the tribological, mechanical, and thermal properties of silicon carbide under various contact conditions at the atomic level. Simulations which incorporate interfacial contact between surface asperities were performed to predict the elastic modulus, thermal conductivity, wear rate, and coefficient of friction. The resulting predicted properties may help enhance the performance of engineered metal-free friction materials against thermal-mechanical failures. The following
Zhang, Yizhan, LeNeave, Cortney, Yi, Yun-Bo
Thermomechanical Instabilities in Metal-Free Friction Materials Using a Nonlinear Transient Simulation Approach2021-01-128610/11/2021
The invention of metal-free friction materials is gaining popularity in the manufacturing of brake pads and clutch friction discs because of the negative factors associated with metals such as copper. To gain more insight into the failure mechanism of the recent invention during brake or clutch applications, a nonlinear transient thermomechanical model is established using Finite Element Code. The model is based on a two-dimensional configuration for an investigation on the onset of TMI (Thermo-Mechanical Instability) during sliding contact in such material. The model is validated by comparing the transient simulation results for a full-contact regime to the result from the existing eigenvalue method. A parametric study is carried out to examine how the thermal conductivities and the elastic moduli influence TMI. The simulation results show that the thermal conductivities in the transverse direction and elastic moduli in the longitudinal direction can stabilize the system. Conversely
Koranteng, Kingsford, Shaahu, Joseph-shaahu, Yi, Yun-Bo
Comparing and analysing the static and thermal characteristics of brake disc for three different materials2021-28-025310/01/2021
In automobiles, the most commonly used braking system is disc brake. In the brake disc, rotor is the rotating part of a wheel's disc brake assembly, against which the brake pads are applied by the driver through mechanical action. So, the disk is the important component in either slowing down or stopping the vehicle. These discs were commonly made of cast iron conventionally. But the limitations with respect to cast iron are that they have less corrosion resistance and heavy in weight. In order to overcome the above-said complications, alternate materials for disc have to be found. The main objective of this paper is to analyze the characteristics of three different materials and compare their results and suggest a suitable material that highly influences the conventional material and has better performance under on-road rigorous braking conditions. In order to find an alternative material for Cast Iron (CI), EN31, Ti-6Al-4V(Ti alloy) acts as a potential candidate in offering great
K, Kaviyarasan, R, Soundararajan, Richter R, Abhisheak, K, Siva, Purusothaman, S, S, Shiva Gurunathan
Numerical and Experimental Investigation of heat transfer enhancement in an off-road radiator using Al2O3 nano fluids2021-28-017710/01/2021
Water and ethylene glycol are considered as conventional coolants from years in automotive industry for engine cooling. With the advancements in nanotechnology, Nano fluids have become prominent in increasing the rate of heat transfer compared to that of conventional fluids. Present study enlightens the CFD simulation of Nano-fluids in a radiator with base fluid as Ethylene glycol- water and Al2O3 as nanoparticles at different volume concentrations. The Nano fluid rheology is simulated in Ansys-Fluent CFD tool using standard k-ε two equation turbulence model with enhanced wall treatment and a standard y plus values. Various available fluent single phase and multiphase models are evaluated and compared with the experimental results in a simple circular pipe to setup the standard simulation methodology for radiator analysis. The effective temperature dependent thermos-physical properties of Nano fluids were estimated from the literatures. The result shows that alumina oxide nano fluids
Dewangan, Nitin, Kattula, Nitin, Kumar PhD, Kiran, naidu, Ramesh
Tribological Behavior of Thermal and Mechanical Composite Reinforced Sisal Characteristics and Influence SiC Filling Material2021-28-027710/01/2021
In order to investigate the possible use of normal capital, we have tried by hand to manufacture sisal fibre polymer composites. Natural fibre composites are reusable, low-cost and biodegradable. Simple source, lesser compactness, superior basic property, lower quality, acceptable physical and mechanical properties, non acidic in environment, make them a good-looking biological substitute for glass, carbon or other artificial fibres. The outcome of SiC on the physical and mechanical properties of organic sisal composite materials is studied in this work. The composite was manufactured with and without SiC, mixing natural sisal fibre with polyester as a reinforcement medium. The investigational results showed that the tensile force of the mixture with 12 % SiC was 2.52 times better than that of the composite devoid of SiC. The collision strength of the 12% SiC merged is 1.72 times higher than that of the SiC pure polyester composite. The physical properties deliberate include thermal
RAJU, GANESAMOORTHY, NATARAJAN, Balaji, Chakaravarthy, Ezilarasan, Samikannu, Poovaragan, R, Soundararajan
A Holistic Approach of Developing New High Strength Cast Iron for Weight Optimization2021-26-024409/22/2021
Cast Iron is being used in various Industries like Automotive, Agriculture, Construction etc., for many decades. Metal casting processes have its unique advantages like ease of heavy weight castings, intricate shapes, higher productivity. Commercially viable (low cost) etc., using wide range of materials like Gray cast iron, Spheroidal cast iron, Malleable cast iron ,cast steel etc., Cast iron have an excellent properties like high dampening capacity, higher thermal conductivity, wear resistance required by many critical applications. These unique combinations will be chosen to serve the purposes both functionally and commercially. However, in last one-decade automotive and agriculture industries are facing issue of fuel economy which directly influenced by the weight of the vehicle. For off-road vehicle like tractors, One of the major contributor in vehicle weight is cast iron. Many material grades and strengthening mechanisms are recently being evolved to optimize the cast iron
Gunalan, Magendran, Anandeswaran, V.A
3D CFD coolant system simulation for a full vehicle drive-cycle2021-26-040709/22/2021
The present work deals with the 3-D, transient, system level CFD simulation of automotive coolant system, which includes actual CAD of radiator, cooling jacket, coolant pump, bypass valve and thermostat valve, using a 3D CFD solver Simerics MP+®. This work is in continuation of the work done by Srinivasan et al. (2017) where wax melting, conjugate heat transfer, Fluid Structure Interaction of the valve had been solved. Thermostat valve was controlled by wax phase change model which incorporates the hysteresis effect of wax melting and solidification. The current model will also include rigorous treatment of cavitation to account for the presence of dissolved gases and vaporization of the liquid coolant. The previous work dealt with simulation of opening and closing cycle of the thermostat/by-pass valve system. A methodology has been developed and implemented where the run-time of such a system has been made considerably faster enabling us to simulate complete drive cycle tests. The
Varshney, Mehul, Ballani, Abhishek, Pasunurthi, Shyam Sundar, Maiti, Dipak, Srinivasan, Chiranth
Simulation based approach to improve the engine oil warmup behavior using exhaust gas during NEDC cycle2021-26-042209/22/2021
During the cold start conditions engine must overcome higher friction loss, at the cost of fuel penalty till the optimum temperatures are reached in coolant and lubrication circuits. The lower thermal capacity of the lubrication oil (with respect to the coolant) inverses the relation of viscosity with temperature, improves engine thermal efficiency benefit. Engine oil takes full NEDC test cycle duration to reach 90°C. This leads to higher friction loss throughout the test cycle, contributing a significant increase in fuel consumption. Increasing oil temperature reduces viscosity, thereby reducing the engine friction. This helps to identify the focus for thermal management in the direction of speeding up the temperature rise during a cold engine starting. This work aims at the study and experiment of an exhaust recovery mechanism to improve the NEDC fuel economy. The objective of the work is to use the exhaust gas energy, post after treatment system to heat up the engine oil temperature
Krishnan, Karthikeyan N., Ramadandi, Padmavathi, M, Vikramraj, Elumalai, Sakthivel
Engine mounted Oil cooler 3D CFD CHT Analysis for predicting Thermal Performance2021-26-035109/22/2021
This paper describes steady state, computationally rigorous, three-dimensional conjugate heat transfer 3D CFD analysis of an engine mounted oil cooler. Thermal performance of an oil cooler is very significant from engine oil consumption, bearings performance etc. In an engine water jacket, coolant flows around and through the oil cooler making the flow three dimensional. Therefore, demanding the need of a 3D CFD analysis for capturing all the flow and heat transfer aspects and thereby accurate prediction of thermal performance. An oil cooler contains intricate turbulators in flow paths and have dimensions varying from as small as 0.25 mm to as large as 300 mm, therefore making the meshing and solution a formidable task. In current work an oil cooler with all the intricate details is modelled in a commercial CFD code. Objective is to develop a solution approach which can predict thermal performance of an oil cooler in an accurate way. An engineering practice with guidelines for geometry
Tawar, Ranjit Ramchandra, Brasmer, Susan, Bedekar, Sanjeev
Drivetrain Lubricants with High Cooling and Efficiency-Boosting Properties for Electric Vehicles2021-01-121509/21/2021
In electric vehicles (EVs), drivetrain lubricants (EV fluids) are often relied upon to aid in cooling the motors. In such cases, the lubricants must provide high cooling performance. They should also improve the efficiency of the transmissions and reduction gearboxes in EV drivetrains. Both requirements can be met by lowering the viscosity of the fluid. This effectively improves the heat transfer coefficient and also helps increase efficiency by reducing churning loss. However, a viscosity that is too low can negatively affect the fatigue life of mechanical parts such as gears and bearings. Another problem is that common defoamers often do not work well with low viscosity oils, and increased foaming can further reduce fatigue life and lead to poor cooling performance and lower efficiency. To solve the issues associated with lower viscosities, we optimized the anti-wear agents, dispersants, and other additives to develop formulations specially designed for EV drivetrains. The result are
Iino, Mari, Tada, Akira, Masuda, Kohei, Matsuki, Shingo, Onumata PhD, Yasushi
Test Method for Determining Cold Cracking of Flexible Plastic MaterialsJ323_202109 (Current)09/15/2021
This SAE Recommended Practice is applicable for determining the cold characteristics of flexible plastic materials, as applicable. It consists of three different methods for determining low-temperature properties of materials depending on type of material and end use. The method used shall be as specified by the contractual parties.
Textile and Flexible Plastics Committee
Advanced developments in solid desiccant coated heat exchangers and their potential applications2021-28-014209/15/2021
To meet the increasing thermal comfort requirements in recent times, applying a solid desiccant coated heat exchanger (SDCHE) air-conditioning system is one of the thrust areas of focus due to its energy efficiency benefits. Fixed stationary bed and rotary wheel desiccant systems are being used widely for dehumidification. In these systems, the increase in the relative humidity of intake process air increases the adsorption heat release from the desiccant, and the desiccant’s temperature increases due to the lower heat transfer efficiency. This effect reduces the COP of these systems since the desiccant adsorption capacity is inversely proportional to the desiccant’s temperature. To overcome the limitations of the fixed stationary beds and rotary wheel desiccant dehumidifiers, SDCHE is a suitable technology for standard vapor-compression air conditioners. These heat exchangers can deliver combined heat and mass transfer between the process air and the working fluid. The process air can
Muthu, Selvaraji, N, Sekarapandian, KANNAIYAN, Ashok, ARIVUKKARASU, Hariprasath
Simulating Thermal comfort for a vehicle2021-28-013209/15/2021
The vehicle HVAC system is designed to meet both the safety and thermal comfort requirements of the passengers inside the cabin. The thermal comfort requirement, however, is highly subjective and is usually met objectively by carrying out time dependent mapping of parameters like the velocity and temperature at various in-cabin locations. These target parameters are simulated for the vehicle interior for a case of hot soaking and its subsequent cool-down to test the efficacy of the AC system. Typically, AC performance is judged by air temperature at passenger locations, thermal comfort estimation alongwith time to reach comfortable condition for human. Simulating vehicle cabin for thermal comfort evaluation is computationally expensive and requires complex cabin material modelling. Coupled simulation between LBM based Powerflow and Finite element based Powertherm solver is employed and discussed here to simulate thermal comfort. Additionally, the human thermal physiology is modelled
Shelar, Sujit, Kandekar, Ambadas, Deshmukh, Ganesh, Nomani, Mustafa, Sivakumar, Vignesh, Nagarajan, Vijaisri
Reduced Heat Leakage Improves Wearable Health DeviceTBMG-3961708/01/2021
Researchers have enhanced a flexible body heat harvester by preventing heat leakage. The harvesters use heat energy from the human body to power wearable technologies. The technology relies on the same principles governing rigid thermoelectric harvesters that convert heat to electrical energy.
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