Browse Topic: Thermodynamics

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Heavy duty hydrogen internal combustion engine emissions development to achieve ultra-low NOx2026-01-0356To be published on 04/07/2026
This paper presents the emissions development of a heavy-duty hydrogen internal-combustion engine (H₂ ICE) targeting ultra-low NOx with a design goal of 20–35 mg/hp-hr. The approach integrates precise air–fuel-ratio control, transient-response enhancements to minimize rich/lean excursions, and advanced thermal management of the engine and aftertreatment, including an electric heater to accelerate light-off and sustain activity at low-load/idle conditions. A diesel-derived aftertreatment system (ATS) is selected to maximize practicality and component commonality, and a unified controls strategy spanning the engine and ATS is implemented to ensure emissions compliance over EPA certification and in-use testing cycles. The aftertreatment solution space is evaluated for catalyst sizing and backpressure while demonstrating particulate matter control without the need for a filter. The paper concludes with emphasis on catalyst aging and durability relative to diesel benchmarks, including long
Shakya, Bijesh, Xu, Hui, Yang, Zhao, stetter, John
Numerical Analysis of Operating Parameters Coupled Effects on Flow Instability Mechanisms at Supercritical Pressure2026-01-0134To be published on 04/07/2026
Supercritical fluids (SCFs) are widely utilized in advanced energy systems due to their exceptional heat transfer characteristics. However, flow instability, particularly near pseudo-critical conditions, poses a significant challenge to their effective applications. Despite extensive research, the coupled effects of thermal and fluid dynamic mechanisms on flow instability remain insufficiently understood, particularly in supercritical water (SCW) systems. This study identifies the onset of flow instability (OFI) in the negative slope region of pressure drop curve during steady-state conditions, analyzing the relationship between pressure drop and mass flow rate. Transient analyses were then conducted to investigate the influence of operating parameters on oscillatory phenomena such as pressure drop oscillations (PDO), density wave oscillations (DWO), and thermal oscillations (ThO). The results show that higher mass flow rates and heat fluxes, reduce pressure oscillations by up to 20
Rehman, Attiq Ur, Ahmad, Hassaan, Du, Xiaocheng, Kanwal, Lubna
Thermal Management of Gasoline Fuel Tanks2026-01-0114To be published on 04/07/2026
This study presents a fully integrated, vehicle-level thermal management model for gasoline fuel tanks, designed to predict transient fuel temperatures, tank wall heating, and vapor generation under real-world driving conditions. The model simulates coupled thermal contributions from exhaust radiation, transient underbody airflow, conductive heat transfer, in-tank pump heating, and dynamic changes in fuel composition and level. Validation against on-road measurements shows strong agreement for fuel temperature and vapor flow profiles. Results confirm that exhaust radiative heating is the dominant thermal load, particularly during the post-shutdown heat soak period. A well-designed heat shield reduced peak tank wall temperature by approximately 27 °C, significantly lowering fuel heating and evaporation. Parametric analysis indicates that while fuel Reid Vapor Pressure (RVP) and tank material influence evaporation, their effect is secondary to external heat mitigation. While this model
El-Sharkawy, Alaa, Asar, Mona, Taha, Nahla, Sheta, Mai
Method of Estimating Electric Vehicle Charge Time Based on Neural Networks2026-01-0382To be published on 04/07/2026
Accurate prediction of electric vehicle charging time is critically hindered by dynamic, non-linear factors including battery aging which is indicated by the State of Health (SOH), substantial power diversion to thermal management systems in extreme temperatures, fluctuating user-defined accessory loads, and hardware limitations of the charging infrastructure. Traditional estimation methods, reliant on static models or predefined calibrations, fail to adapt to these real-world variables, leading to inaccurate predictions and user dissatisfaction. This paper presents a novel data-driven estimation framework utilizing a tailored feedforward neural network architecture specifically designed for this complex task. The model processes a sensitive set of inputs—including initial State of Charge (SOC), SOH, battery temperature, charging station power level and user-selected target SOC—to effectively capture the intricate, non-linear interdependencies governing the charging process. The
Xie, Zhentao, shojaei, Sina, Weslati, Feisel
Guidelines for Interior Material Selection to Enhance Thermal Safety in Electric Vehicles2026-01-0249To be published on 04/07/2026
Due to the rapid advancement of electric vehicles, the role of material selection has become very critical for ensuring passenger safety, particularly in mitigating risks associated with Lithium-Ion (Li-Ion) battery thermal runaway. Unlike internal combustion engine (ICE) vehicles, electric vehicles require interior materials that provide superior fire resistance, thermal insulation, and minimal smoke emission to protect vehicle occupants in extreme thermal events. This paper examines the importance of selecting fire-resistant materials, thermally stable polymers, and low-toxicity materials that can slow fire propagation, reduce interior temperatures, and reduce hazardous gas emissions. Through the integrating of materials with high thermal stability, self-extinguishing properties, and heat-reflective coatings, manufacturers can enhance vehicle interior safety, improve passenger protection, and optimize energy efficiency.
El-Sharkawy, Alaa, Taha, Nahla, Asar, Mona, Sheta, Mai
The Impact of Extreme Ambient Temperatures on Electric Vehicle Performance in the Kingdom of Saudi Arabia2026-01-0133To be published on 04/07/2026
The rapid expansion of Saudi Arabia’s electric vehicle sector driven by manufacturers such as CEER Lucid Tesla and BYD necessitates evaluating vehicle performance under extreme thermal conditions. This study investigates the impact of high ambient temperatures on electric vehicle operation by analyzing a 60 kWh NMC battery pack under representative Riyadh summer conditions of up to 47 °C using MATLAB Simulink simulations. The results show that elevated temperatures accelerate state of charge (SOC) depletion and increase battery internal resistance. To maintain safe operating limits the BTMS must operate continuously consuming up to 20 percent of the available energy. Cooling demand increases nonlinearly with temperature exceeding 40 kW at 50 °C which leads to significant parasitic losses and a 15 to 20 percent reduction in driving range. At the system level this increased energy demand raises charging frequency and intensifies electricity load during peak summer periods thereby
Bedywi, Lama Mohammed A, AlJuhani, Haneen, Duan, Chen, AbdulNour, Bashar
Simulation of Conjugate Heat Transfer using the Lattice Boltzmann Method2026-01-0135To be published on 04/07/2026
Flow simulation with conjugate heat transfer, which involves fluid flow, conduction, and radiation in solid components, is a critical capability that helps engineers design and evaluate cooling systems for heat-generating components such as brakes, powertrains, batteries, and power electronics for both gasoline and electric vehicles. For this study, we utilize PowerFLOW™, featuring its novel native thermal solver, which models both fluid and solid domains within a single model. For the flow domain, we use the Lattice Boltzmann Method with VLES turbulence modeling based on the RNG k-epsilon method. And for the solid domain, the finite volume method with second-order accuracy for thermal conduction and a surface-to-surface radiation for the surfaces. This approach not only leads to a more integrated and streamlined workflow but also enables an accurate modeling of conduction and radiation. In this study, we demonstrate the accuracy of the conjugate heat transfer simulation methodology
Mukutmoni, Devadatta, Shock, Richard, Li, Han, Wanderer, John
Effect of injector tip temperature on methanol spray dynamics during cold-start conditions2026-01-0340To be published on 04/07/2026
Methanol is one of the most readily produced e-fuels and remains in liquid form at ambient conditions, making storage and transportation relatively simple. In the marine sector, methanol has already been actively adopted as a pathway toward carbon neutrality. For automotive sectors, methanol offers significant potential for carbon emission reduction owing to its higher Octane-number and lower carbon content compared with gasoline. However, its high latent heat of vaporization and low vapor pressure suppress evaporation at low ambient temperatures, leading to increased emissions during cold-start operation. To address this issue, previous studies have explored heating the injector tip or fuel rail to enhance evaporation and atomization. The present study focuses on visualizing and quantifying the improvement in methanol evaporation characteristics under cold-start conditions by applying controlled heating to the injector tip. Experiments were conducted in a constant volume chamber where
Lee, Seungwon, Kim, Hyunsoo, Bae, Sumin, Hwang, Joonsik, Bae, Choongsik
Identifying pressure drop and heat transfer correlations for a liquid-cooled lithium-ion battery pack model of electric vehicles under hot-cold driving2026-01-0394To be published on 04/07/2026
The performance of a full lithium-ion battery (LIB) pack with its cooling system depends on the pressure drop and heat transfer from the cell to ambient air through coolant, cooling flow channels, air gaps, and pack cases. Predicting the LIB pack responses (i.e: voltage, SOC, temperature) requires accurate predictions of the thermal performance between the cells and ambient air and cooling flow behaviour inside the pack, respectively, since the pack has several thousand cells, cooling channels, and channel pipe bends. This work presents a systematic approach to identifying heat transfer and pressure drop ∆P correlations that capture the real-time thermal-electrical performance of a mass-produced LIB pack under constant speed (in winter) and transient driving (in summer). A vehicle test is conducted using a Tesla Model Y, a long-range, dual-motor model equipped with a 75-kWh LIB pack. The LIB pack's thermal and electrical performance is recorded under both constant speed and transient
Sok, Ratnak, Kusaka, Jin
AirCARE: Assessing the Impact of an Integrated Air Purification System on Vehicle Thermal Management2026-01-0272To be published on 04/07/2026
The increasing concentration of atmospheric pollutants in urban environments necessitates innovative solutions to mitigate their impact on public health and the environment. This work presents the AirCARE project, which investigates the integration of a catalytic converter and a particulate filter with a vehicle's radiator to create an active air purification system. The primary objective is to evaluate the feasibility and performance implications of this integrated system on the vehicle's thermal management. A comprehensive methodology combining computational modeling and experimental testing was employed. A 1D longitudinal vehicle model was developed to simulate the powertrain's heat generation and the cooling system's performance under various representative driving conditions. This model allows for a parametric study of the radiator, assessing the impact of the additional components on its heat exchange efficiency. Concurrently, experimental tests were conducted on a radiator to
de Carvalho Pinheiro, Henrique, Sartoretti, Enrico
Quantifying the Impact of Towing on BEV Energy Use: Instrumented On Road Testing and Chassis Dynamometer Reproduction2026-01-0431To be published on 04/07/2026
Electrification is rapidly entering all vehicle classes, including light- and heavy-duty trucks designed for heavy towing capabilities. Still, the quantitative impact of towing on battery-electric vehicle (BEV) energy use and range remains under-characterized. We conducted controlled towing tests with a Ford F-150 Lightning using two trailers of different sizes and varying payloads to isolate aerodynamic and mass effects across the vehicle’s rated towing capacity. The vehicle was instrumented at the CAN bus level to capture motor power, torque, speed, and other related internal signals. On-road testing consisted of repeated back-and-forth passes on level, straight road segments at set speeds focusing on highway operation, where aerodynamic drag is stronger and real-world towing use cases occur. From these data, we extracted road load equations and dynamometer coefficients for each trailer combination, then reproduced equivalent conditions on a four-wheel drive chassis dynamometer
Timermans Ladero, Inigo
Optical investigation of Argon Power Cycle (APC)2026-01-0328To be published on 04/07/2026
The growing global demand for energy, combined with the urgent need to reduce greenhouse gas (GHG) emissions, is driving the development of alternative combustion technologies across transport sectors. Low- and zero-carbon fuels such as methanol, ammonia, and hydrogen are being explored as viable replacements for fossil fuels in internal combustion engine (ICE) applications. Among these, hydrogen stands out due to its wide flammability range and fast, carbon-free combustion. Research is ongoing to understand how hydrogen and other alternative fuels can be used most efficiently in ICEs. One promising concept is the Argon Power Cycle (APC), which could enable high-efficiency, zero-emission combustion in ICEs. In this approach, argon replaces air as the working fluid. Argon’s higher specific heat ratio (1.66 vs. 1.4 for air) and lower thermal conductivity both help increase efficiency. The absence of nitrogen also means NOx emissions are eliminated. The APC system is relatively simple
Kapp, Joakim, Cheng, Qiang, Vuorinen, Ville, Kaario, Ossi
Thermal Management of Battery Modules under Fast Charging2026-01-0399To be published on 04/07/2026
Battery modules operate under diverse and complex conditions, such as driving cycles and fast charging. In these scenarios, effective thermal management is critical to ensuring safety and extending the battery's lifespan. Fast-charging scenarios present a particular challenge due to the complex current control strategies that strongly influence cell temperature distribution, making thermal uniformity a key concern. This study presents a coupled electrochemical-thermal simulation framework based on the DCiR (direct current internal resistance) model to examine heat generation and temperature responses during fast charging. The model incorporates heat conduction pathways and the structural layout of the module, enabling the evaluation of thermal mismatch risks and the optimization of module design and charging strategies. The findings offer practical insights for battery thermal management and the development of advanced fast-charging strategies.
Xiao, Fangzhi, CHEN, Guijie, ma, Shihu, Hu, Xiao, SONG, Shujun, Wakale, Anil Bhaurao
Development of a virtual test rig to evaluate thermal management of a battery-electric vehicle under battery heating-cooling modes2026-01-0416To be published on 04/07/2026
A battery-electric vehicle (BEV) has multiple powertrain components (battery, inverter, e-motor), a thermal management system (compressor, heat exchanger, cabin heating, ventilation, and air-conditioning), and a vehicle body, among others. Vehicle testing is time-consuming, and also changing powertrain components during the testing and design process is costly. Simulation models (aka virtual or simulation test rig) have been widely used for efficient vehicle design. This work presents a systematic approach to developing a virtual test rig to evaluate the thermal performance of battery-electric vehicles. A Tesla Model Y is tested in a chassis dynamometer, and the measured vehicle performance data are used as boundary conditions for the complete vehicle model. The detailed lithium-ion battery (LIB) pack model, including its cooling system, was developed and calibrated using various transient driving cycle data. The HVAC model uses a simplified controller to maintain the cabin temperature
Sok, Ratnak, Kusaka, Jin
Thermal Performance of Natural Fiber Hybrid Composites for Automotive Insulation Applications2026-01-0244To be published on 04/07/2026
This study investigates the thermal conductivity of natural-fiber-based hybrid polymer composites with potential automotive insulation applications. With the increasing demand for lightweight, sustainable, and thermally efficient materials in vehicle cabins, under-hood systems, and electric vehicle battery enclosures, natural fiber composites present a promising alternative to conventional glass-fiber composites. Three distinct composite configurations were fabricated: pure glass, glass-jute hybrid, and glass-jute-coir hybrid, using general-purpose polyester resin as the matrix. The composites were manufactured using the hand lay-up method. Thermal conductivity measurements were conducted using the ASTM C177 guarded hotplate method on composite plates. Results indicate that the hybrid composite with glass, jute, and coir fibres has the lowest thermal conductivity, making it the most effective for insulation applications. This study demonstrates that natural fibre-reinforced composites
Mache, Ashok, Salve, Aniket, Chinchanikar, Satish, Borse, Hardik, Deshmukh, Omkar, Mahadikpatil, Siddhi, Kulkarni, Aparna
Thermal Characterization of an Automotive High Voltage Junction Box2026-01-0390To be published on 04/07/2026
The high voltage battery junction box (HVJB) controls and protects the high voltage connections of the battery pack to the traction, auxiliary and charging systems. HVJBs are composed of busbars, contactors, fuses and other protection systems. The health of the HVJB is paramount to ensure performance and reliability of electric vehicles. However sensing and monitoring in the HVJB is often lacking due to cost, causing limited capability of the vehicle controller to estimate the status and health of the unit. This publication focuses on the experimentation of an automotive HVJB to characterize the operation and build the foundation for the development of prognostic algorithms for HVJB. A production HVJB has been acquired and heavily instrumented. Extensive testing are performed in adiabatic and in ambient conditions at various current levels for various durations of operation. The testing setup was calibrated and iterated based on preliminary results, and the testing conditions were
Arigo, Sam, Borgerson, Joe, D'Arpino, Matilde, ZHU, Di, Zhang, Liwen
Propulsion System Design Considerations for HEV versus EV Applications2026-01-0641To be published on 04/07/2026
The design and development of EVs and HEVs has become a growing issue recently due to concerns about pollution and dependence on non-renewable fossil fuels. Accordingly, General Motors (GM) has an evolving vehicle electrification plan over the past several decades and into the future to deliver low-cost and efficient EVs and HEVs. Propulsion system requirements for the applications of EV and HEVs are quite different and therefore, the design principles and directions are also distinct between these cases. From micro-hybrid and full plug-in hybrid applications to full EV applications, design requirements, strategies and outcomes can widely vary. Continuous and peak duty are substantially different depending on the application of the vehicle. Motor operational duty is significantly higher for EV compared to the electric motor of a hybrid electric vehicle. Motor torque, power and efficiency requirements are also higher for EV motors, which greatly influences the choice of motor type and
Momen, Faizul, Jensen, William, Das, Shuvajit, Chowdhury, Mazharul, Alam, Khorshed, Anwar, Mohammad, Reinhart, Timothy
Predictive Maintenance of EV Drive Unit Oil Pumps via Machine Learning on Fleet Telemetry2026-01-0161To be published on 04/07/2026
The reliability of Drive Unit (DU) oil pumps is critical to the performance and safety of electric vehicles, as these pumps provide essential lubrication and thermal management. However, direct physical sensors for real-time pump health monitoring are absent in current architectures, making early fault detection particularly challenging. To address this limitation, we present a novel, data-driven anomaly detection framework that leverages large-scale customer fleet telemetry and advanced machine learning to identify incipient pump degradation that traditional diagnostic methods often fail to capture. The core of the approach is an XGBoost regression model trained on time-series features—including commanded pump speed, oil temperature, and historical pump current—to predict expected current behavior under nominal conditions. Deviations are quantified using the Mean Absolute Percentage Error (MAPE) between predicted and actual currents, providing a continuous and interpretable measure of
Li, Jingman, Yao, Mengqi, Rahimi, Sahil, Lin, Joanne
Beyond PFAS: Unlocking the Potential of R290 and R744 for EV Efficiency2026-01-0127To be published on 04/07/2026
The anticipated PFAS ban in the US by 2029 has created a need to evaluate alternative refrigerant solutions for automotive thermal management systems. This work compares three candidates—Propane (R290), Carbon Dioxide (R744), and R1234yf—through system-level testing and demonstration projects. R1234yf remains the current industry baseline. Test results show that Propane (R290) delivers comparable efficiency while offering a significantly lower global warming potential. However, its flammability presents integration challenges, not present with R1234yf or R744. CO₂ (R744) demonstrated promising performance as well. In AVL’s Refrigerant Cooling Project, direct CO₂ cooling battery plate simplified the thermal system architecture and provided adequate cooling capacity during high charging loads. To address safety concerns with Propane, AVL developed mitigation measures including rapid leak detection, robust containment strategies, and optimized circuit layouts designed to reduce ignition
bires, Michael, Possegger, Jonathan
Performance Analysis and Optimization of a Drizzling-Based Evaporative Cooling for Enhanced Thermal Management of FCEV Stack2026-01-0115To be published on 04/07/2026
In response to increasingly stringent global emissions regulations, including Euro 7, the automotive industry is intensifying its focus on eco-friendly propulsion systems. Among them, hydrogen fuel cell electric vehicles (FCEVs) have emerged as a promising alternative in the commercial transport sector, offering high energy density, rapid refueling, long driving range, and minimal payload limitations. However, the operational efficiency and durability of fuel cell stacks heavily depend on effective thermal management, and insufficient cooling can lead to power degradation and reduced lifespan. This study proposes a novel thermal management strategy that enhances stack cooling performance by directly applying fuel cell discharge water onto the radiator surface, utilizing latent heat of evaporation. To overcome the structural complexity and control challenges of high-pressure spray systems, a gravity-driven low-pressure drizzling method was adopted, achieving both system simplification
Lee, Dongkeon, Seo, Jungmin, Lee, Seogjun, Son, Dongwook, Lee, Hoseong, Shin, Yoonhyuk, Kang, Hyunsung
Modeling Non-Uniform Temperature Distribution in Lithium-Ion Batteries2026-01-0120To be published on 04/07/2026
Effective thermal management is critical to the performance, lifespan, and safety of lithium-ion batteries in electric vehicles (EV). Transient and non-uniform temperature distributions within cells accelerate degradation, cause pack imbalance, and reduce efficiency. Localized hotspots, in particular, promote lithium plating, solid electrolyte interface (SEI) growth, and other failure mechanisms. Persistent non-uniformities increase the likelihood of thermal runaway under high-stress operation. To address these challenges, this work develops a one-dimensional thermal model that captures heat generation and dissipation under dynamic operating conditions, incorporating both conduction within the cell and active convective cooling. Using a DFSS-based approach, we evaluate design and cooling strategies that minimize temperature differentials while maintaining acceptable operating ranges. The findings provide practical guidance for battery thermal management system design, emphasizing
El-Sharkawy, Alaa, Asar, Mona, Serpento, Stan, Sheta, Mai
Advancing Safe Battery Design through Experimental Cell Characterization of Thermal, Electrical and Mechanical Properties2026-01-0408To be published on 04/07/2026
Lithium-ion batteries are critical to electric vehicles and grid-scale energy storage. Safe design of battery systems relies on accurate simulation of battery thermal runaway under electrical, thermal, and mechanical abuse. A predictive battery simulation requires the characterization of electrical, thermal, and mechanical properties of the battery at the full cell and cell-component levels. In this study, a commercial cell from an electric vehicle was disassembled, and testing was conducted to support both homogenized and detailed computational models. At the cell level, electrical properties were characterized using Hybrid Pulse Power Characterization (HPPC) testing to assess the cell power capability. Cell punch tests were conducted to characterize mechanical behavior under deformation. These tests were used to develop a multi-physics homogenized cell model. On the other hand, detailed cell modeling that includes different component layers could help users understand localized cell
Challa, Vidyu, Rostami-Angas, Masoud, kong, Kevin, Wang, Leyu, Reichert, Rudolf, Kan, Cing-Dao
Radar-Based Dynamic Pixel Activation in Camera Sensors for Optimized Image Processing, Power Efficiency, and Thermal Management2026-01-0047To be published on 04/07/2026
This paper presents a radar-based dynamic imager pixel activation method designed to optimize image processing efficiency, power consumption, and thermal management in automotive In-cabin monitoring systems (DMS and OMS). By integrating radar sensing with high-resolution cameras, the proposed approach selectively activates image sensor pixels only within radar-identified regions of interest, such as moving occupants or key cabin areas. This selective pixel activation substantially reduces the computational workload and data bandwidth required, as the camera transmits high-resolution data solely for relevant zones while maintaining lower resolution or deactivating pixels elsewhere. The fusion of radar and camera data enables adaptive sensor control that caters to distinct scenarios, including driver gaze tracking and passenger monitoring, thereby enhancing DMS and OMS functionality. The architecture supports mounting configurations such as headliner or rearview mirror installations
Kasarla, Nagender Reddy, Patel, Krunal, Balaraman, Nirmal Kumar
CAE-based Electro-Thermal Characterization and Design Optimization of Automotive Inverter Busbars2026-01-0642To be published on 04/07/2026
High power density demands in automotive inverters need precise thermal management to ensure efficiency, reliability and extended component lifetime. This paper presents a systematic, integrated electro-thermal workflow utilizing Computer-Aided Engineering (CAE) tools to characterize and optimize internal inverter components by directly linking electrical performance to thermal behavior. The methodology comprises three main steps: first, detailed frequency-dependent electrical parameters (RLCG, Z, S) and current density maps are extracted using computational calculations by ANSYS HFSS and ANSYS Q3D Extractor. Second, these parameters inform comprehensive power loss calculations (conduction, dielectric, switching), which are then mapped onto detailed 3D thermal fields using Computational Fluid Dynamics (CFD) through ANSYS Icepak. Finally, the results are analyzed to identify critical components and inform targeted design modifications. The workflow's effectiveness is demonstrated
Oliveira, Felipe, Aguiar, Cláudio, Justino, Marco, Tarrago, Vinicius, Almeida, Oberti
Accelerating Electrification Through Modular Propulsion: GM’s Strategy for BEV and BET Platforms2026-01-0410To be published on 04/07/2026
General Motors continues to advance its electrification strategy through the development of scalable Battery Electric Vehicle (BEV) and Battery Electric Truck (BET) platforms. This paper highlights GM’s latest BEV and BET products that leverage shared Drive Unit (DU), Rechargeable Energy Storage System (RESS), and integrated power electronic (IPE) components across multiple vehicle programs. By adopting a modular and commonized propulsion architecture, GM achieves significant benefits in manufacturing efficiency, cost optimization, and product flexibility. The shared DU, RESS, and IPE components are engineered to meet diverse performance requirements while maintaining high standards of energy efficiency, thermal management, and durability. This approach enables rapid deployment of electrified solutions across various segments, from passenger vehicles to full-size trucks, without compromising on capability or customer experience. The paper outlines the technical rationale behind
Liu, Jinming, Sevel, Kris, Anwar, Mohammad, Oury, Andrew, Welchko, Brian, Gagas, Brent
Numerical Framework for Predicting Power Loss and Oil Flow Dynamics in Dip-Lubricated Gear Systems2026-01-0411To be published on 04/07/2026
Oil churning and windage power losses in dip-lubricated gearboxes can significantly improve overall transmission efficiency, particularly at high rotational speeds. As modern gearbox systems are pushed toward higher efficiency and reliability, understanding and predicting these losses becomes increasingly important. In addition to energy dissipation, the associated multiphase flow phenomena—such as oil splashing, thin film formation along gear surfaces, and aeration of the sump—strongly influence lubrication effectiveness, heat transfer, and component durability. Capturing these effects requires a robust numerical strategy that can resolve both power loss mechanisms and multiphase flow dynamics with sufficient accuracy. In this study, a single spur gear is numerically analyzed under varying oil depths and rotational speeds to quantify total power loss and investigate oil flow patterns. The computational approach employs a volume-of-fluid multiphase framework, and the predictions are
Mahyawansi, Pratik J., Haria, Hiral, Pandey, Ashutosh, KHAJEH HOSSEINI D, NAVVAB
Leveraging Large Language Models for CAD Automation and Multi-Objective Optimization of Automotive Heat Exchangers2026-01-0506To be published on 04/07/2026
The design of automotive heat exchangers is a critical challenge, requiring the careful balance of thermal performance, aerodynamic efficiency, structural integrity, and manufacturability. Traditional design processes rely heavily on manual CAD modeling and iterative simulations, which are both time-intensive and computationally demanding. Recent advances in artificial intelligence, particularly in Large Language Models (LLMs) and Transformer-based architectures, open new possibilities for automating these tasks. This work introduces a novel framework that integrates LLMs with CAD kernels to generate parametric heat exchanger geometries directly from natural language descriptions. The models are automatically exported into standard formats for computational fluid dynamics simulations and seamlessly incorporated within a multi-objective optimization pipeline. By coupling natural language-driven CAD automation with advanced optimization techniques, the framework enables rapid exploration
Chaudhari, Prathamesh, Tovar, Andres
Optimization of Engine Cooling System for Improved Fuel Efficiency and Vehicle Marketability2026-01-0297To be published on 04/07/2026
Effective thermal management in internal combustion engines is essential for meeting increasingly stringent global emissions regulations and fuel efficiency standards. This paper presents a comprehensive solution to enhance engine thermal management performance by addressing key system aspects, including coolant circuit architecture, Integrated Thermal Management Module (ITM) control strategies, port-specific flow management, zero-flow operation, and standardization of HVAC (Heating, Ventilation, and Air Conditioning) settings. The research was conducted on a newly developed engine platform, where a suite of advanced thermal management measures was applied and verified through both vehicle and bench testing. Key improvements included reducing the thermal mass of the coolant circuit to enable faster warm-up of the engine and major components, as well as refining ITM control logic through linear mapping and signal filtering for more precise target coolant temperature regulation. Enhanced
Lee, ChangJoo, LEE, KyuMin, Kim, Seonyeong, Nam, Choonho, YOO, JiHun
Predictive Modeling and Sensitivity Analysis of Thermal Runaway in 800V Lithium-Ion Battery Pack Module Using DFSS Methodology2026-01-0124To be published on 04/07/2026
Thermal runaway in high-voltage lithium-ion battery modules should focus on critical safety and design challenges in electric vehicle applications, which need predictive methods that enhance passenger safety and support regulatory compliance. The primary purpose of a lithium-ion battery in an electric vehicle is to provide reliable energy storage while maintaining safe operation under different operating conditions. This study proposes a Design for Six Sigma (DFSS) methodology to virtually predict and correlate thermal runaway and its propagation in an 800V high-power lithium-ion battery module. Conventional propagation analysis relies heavily on physical testing, whereas the DFSS-based virtual framework enables cost-effective evaluation at early design stages. Input factors included are heat transfer pathways, which are sensitive to the temperature changes, as well as thermal propagation time. Control factors are the design or process parameters that engineers use to establish the
Dixit, Manish, Raja, Vinayak, Gudiyella, Soumya
Thermal Management Simulation of Liquid-Cooled Energy Storage Batteries Using a Reduced-Order Model2026-01-0122To be published on 04/07/2026
A linear time-invariant (LTI) reduced-order model (ROM) based on 3D CFD offers high accuracy for simulating energy storage battery thermal behavior under variations in ambient temperature, initial temperature, coolant inlet temperature, cell heat generation, and Joule heating. However, it cannot capture coolant flow rate fluctuations, which are essential for liquid cooling start–stop conditions in energy storage containers. To address this, we use an enhanced LTI+HTC ROM, which incorporates flow-rate-dependent heat flux at the fluid–solid interface into the LTI ROM. This is achieved by establishing a correlation between the coolant flow rate and the interface heat transfer coefficient (HTC). We further improve model fidelity by applying interface heat flux distribution features extracted from CFD. Comparisons with 3D CFD results demonstrate that the LTI+HTC ROM is highly accurate and significantly reduces computational cost, making it a practical tool for thermal management studies
guo, Jia, CHEN, Guijie, ma, Shihu, Hu, Xiao, Jing, Li, SONG, Shujun, Huang, Long
Application of DFSS for Optimizing Thermal Protection in Electric Vehicles During Battery Thermal Runaway Events2026-01-0142To be published on 04/07/2026
Battery thermal runaway is a major safety concern in electric vehicles because of the extreme heat and hazardous gases released during cell failure. These venting events can quickly raise the temperature of the battery enclosure and cabin floor, threatening occupant safety. To address this challenge, this study employs the Design for Six Sigma (DFSS) methodology to design and optimize a thermal protection system that delays and limits heat transfer to the cabin. A physics based transient heat transfer model was combined with DFSS principles to systematically evaluate insulation materials, shield layouts, surface emissivity, and layer geometry. An L 18 orthogonal array was used to identify key parameters and quantify their influence on thermal robustness. The optimized architecture reduced cabin floor temperature rise under severe runaway conditions (600–900 °C vent gas), meeting occupant egress safety requirements. Findings confirm DFSS as an effective framework for developing high
El-Sharkawy, Alaa, Asar, Mona, Taha, Nahla, Sheta, Mai
Thermo-Mechanical Analysis of 1U CubeSat Structures using ANSYS: Insights for Mobility Applications2026-01-0145To be published on 04/07/2026
Particularly for small satellites like CubeSats, the growing commercialization and downsizing of space technology have brought both new opportunities and problems in the areas of heat management and structural design. A Single Unit (1U) CubeSat structure's design and simulation analysis are presented in this work, with an emphasis on the structure's mechanical and thermal performance during launch and orbit. The CubeSat platform, which is frequently constructed using commercial off-the-shelf (COTS) components, needs robust and lightweight structures that can handle mechanical loads and high temperature changes. In order to conduct mechanical stress loading (MSL) and thermal analysis (TA) on a 3D CubeSat model, this work uses ANSYS in a simulation-driven manner. Geometry modeling, meshing, boundary condition application, and simulation of important space environment elements including microgravity, solar radiation, and launch-induced stresses are all part of the process. The findings
Hussain, Muzammil, Azeem, Naqash, Adeel, Muhammad
Conjugate Heat Transfer Modeling for Predicting Thermal Behavior of X76 Emotor Windings2026-01-0118To be published on 04/07/2026
A computational study based on a conjugate heat transfer (CHT) method in SimericsMP+ was performed to predict the winding temperatures in an X76 emotor. In this study, the thermal load was represented in the simulation through the solution of electromagnetic equations in SimericsMP+, where heat generation was driven by root-mean-square (RMS) current, while liquid cooling was applied at flow rates ranging from 1 LPM to 6 LPM. Simulations were conducted to measure the temperature on three thermocouple locations on each side of the winding crown and weld regions under steady operation. The computational strategy employed a loosely coupled approach. A fluid-only simulation was first carried out to establish stable flow conditions, followed by coupling with solid conduction where the winding acted as the heat source. The predicted temperature distributions were then compared with test data. Results obtained show good agreement, with differences remaining within an acceptable range, thereby
Jia, Kun, Schlautman, Jeff, Srinivasan, Chiranth
Analysis of Heat Transfer in Microchannel Heat Sink with Porous Fins for Battery Cooling Module2026-01-70172/27/2026
Heat sinks are essential cooling components in the battery thermal management systems (BTMS). Porous fin microchannel heat sinks can achieve high heat transfer rates in confined spaces, offering significant potential for practical applications. In this study, a modified-porous fin microchannel heat sink for BTMS is numerically simulated to examine its fluid dynamics and thermal exchange properties. By partially and uniformly filling metal foam in solid fins, the temperature is reduced, the Nusselt number is increased, and the comprehensive performance is enhanced. Compared with solid fins, the modified design is shown to yield a maximum Nusselt number improvement of 153.6%, accompanied by a peak performance evaluation coefficient reaching 1.92. Thermal analysis is conducted by considering both structural optimization and coolant flow behavior. Effects of metal foam filling width and height are investigated. The fluid dynamics and thermal exchange properties of the modified structure
Zhang, Liyuan, Lai, Huanxin
Development of Smart Climate Control with Multiple Level Auto Calibrations2026-28-00082/12/2026
Electric Vehicles (EVs) are rapidly transforming the automotive landscape, offering a cleaner and more sustainable alternative to internal combustion engine vehicles. As EV adoption grows, optimizing energy consumption becomes critical to enhancing vehicle efficiency and extending driving range. One of the most significant auxiliary loads in EVs is the climate control system, commonly referred to as HVAC (Heating, Ventilation, and Air Conditioning). HVAC systems can consume a substantial portion of the battery's energy—especially under extreme weather conditions—leading to a noticeable reduction in vehicle range. This energy demand poses a challenge for EV manufacturers and users alike, as range anxiety remains a key barrier to widespread EV acceptance. Consequently, developing intelligent climate control strategies is essential to minimize HVAC power consumption without compromising passenger comfort. These strategies may include predictive thermal management, cabin pre-conditioning
Mulamalla, Sarveshwar Reddy, SV, Master Eniyan, M, Nisshok, Anugu, Anil, E A, Muhammed, Guturu, Sravankumar
Laboratory Testing of Vehicle and Industrial Heat Exchangers for Heat Transfer and Pressure Drop PerformanceJ1994_202602 (Current)2/12/2026
This SAE Recommended Practice is applicable to all heat exchangers used in vehicle and industrial cooling systems. This document outlines the tests to determine the heat transfer and pressure drop performance of heat exchangers under specified conditions. This document has been reviewed and revised by adding several clarifying statements to Section 4.
Cooling Systems Standards Committee
Genetic Algorithm Based Optimization of Chaboche Kinematic Hardening Parameters along with the Validation of FE Model through Characterized Crack Initiation2026-28-00862/12/2026
In the context of electro-mobility for commercial vehicles, the failure analysis of a connector panel in a DCDC converter is crucial, particularly regarding crack initiation at the interface of busbar and plastic component. This analysis requires a thorough understanding of thermo-mechanical behavior under thermal cyclic loads, necessitating kinematic hardening material modeling to account for the Bauschinger effect. As low cycle fatigue (LCF) test data is not available for glass fiber reinforced polyamide based thermoplastic composite (PA66GF), we have adopted a novel approach of determining non-linear Chaboche Non-Linear Kinematic Hardening (NLK) model parameters from monotonic uniaxial temperature dependent tensile test data of PA66GF. In this proposed work a detailed discussion has been presented on manual calibration and Genetic Algorithm (GA) based optimization of Chaboche parameters. Due to lack of fiber orientation dependent test data for PA66GF, here von Mises yield criteria
Basu, Parichay, Srinivasappa, Naveen
Performance Evaluation of a Novel Coolant Channel Configuration for Liquid Based Battery Thermal Management in Electric Vehicles2026-28-00422/12/2026
The performance and longevity of lithium-ion (Li-ion) batteries in electric vehicles (EVs) are critically dependent on effective thermal management. As internal heat generation during charge and discharge cycles can lead to uneven temperature distribution, exceeding optimal operating limits (25 - 40°C) can significantly degrade battery performance and lifespan. This study presents a performance evaluation of a novel liquid-based Battery Thermal Management System (BTMS) featuring a dual-directional coolant channel configuration designed to enhance thermal uniformity and heat dissipation. The proposed configuration combines horizontal and vertical coolant passages in an indirect cooling layout to address the limitations of conventional serpentine-type channels. A comprehensive thermal analysis was carried out under realistic loading conditions using three coolant types: water, ethylene glycol- based G48, and graphene-enhanced water nanofluids. These were evaluated for thermal
Selvan, Arul Mozhi, Periyasamy, Muthukumar, R, Thiruppathi, Prasad S, Hari, Raghav, R, Boddu, Sriram Pydi Aditya
Numerical Study of Battery Pack Cooling for Electric Vehicles2026-28-01102/12/2026
This study presents a systematic CFD-based investigation of air-cooled lithium-ion battery pack thermal management using a novel U-shaped channel. The U-shaped domain was selected due to its ability to promote recirculation and uniform air distribution, which enhances cooling effectiveness compared to conventional straight and Z-type channels. A systematic parametric optimization of inlet position and airflow velocity was performed to minimize hotspot formation and improve temperature uniformity. Results reveal that shifting the inlet from 30 mm to 20 mm and increasing velocity from 2 m/s to 3 m/s reduced the maximum battery temperature by 3.46 K, from a baseline of 333 K to 329.54 K, while maintaining minimal pressure drop. These findings highlight that strategic control of inlet parameters can yield significant thermal improvements with high cost-effectiveness and geometric simplicity.
PC, Murugan, J, Sivasankar, W, Beno Wincy, G, Arun Prasad
Experimental Study of Entrainment by Hydrogen-Like Impinging Jets of Various Types in a Confined Compartment03-19-01-00062/9/2026
Recent literature has highlighted significant heat transfer losses and elevated particle formation in direct-injection hydrogen engines, particularly when compared to hydrocarbon fuels such as methane. These challenges are attributed to hydrogen’s unique physicochemical properties, notably its short flame quenching distance and high diffusivity, as well as the interaction between the hydrogen jet and lubricated cylinder surfaces, which promotes lubricant entrainment into the combustion chamber. Consequently, a fundamental understanding of these entrainment mechanisms is a prerequisite for developing engineering strategies to enhance thermal efficiency and mitigate particle formation. The reported study investigates gaseous jet–air interaction in a confined volume to elucidate the influence of injector geometry on jet propagation and air entrainment. Three distinct jet configurations were examined: the wide hollow-cone, the narrow hollow-cone, and the round jets. The jet evolution and
Ben David Holtzer, Ben Binyamin, Tartakovsky, Leonid
The Control of Excess Humidity in Avionics CoolingARP987B (Current)1/26/2026
This Aerospace Recommended Practice (ARP) outlines the causes and impacts of moisture and/or condensation in avionics equipment and provides recommendations for corrective and preventative action.
AC-9 Aircraft Environmental Systems Committee
Aircraft Thermal Management System EngineeringAIR5744 (Current)1/21/2026
The intent of this report is to encourage that the thermal management system architecture be designed from a global platform perspective. Separate procurements for air vehicle, propulsion system, and avionics have contributed to the development of aircraft that are sub-optimized from a thermal management viewpoint. In order to maximize the capabilities of the aircraft for mission performance and desired growth capability, overall system efficiency and effectiveness should be considered. This document provides general information about aircraft Thermal Management System Engineering (TMSE). The document also discusses approaches to processes and methodologies for validation and verification of thermal management system engineering. Thermal integration between the air vehicle, propulsion system, and avionics can be particularly important from a thermal management standpoint. Due to these factors, this report is written to encourage the development of a more comprehensive system
AC-9 Aircraft Environmental Systems Committee
Strategic & Frugal Technology Approach to Meet the Stringent CPCB-IV+ Emission Norms2026-26-00591/16/2026
In CPCB-IV+ Emissions regulations NOx & PM are reduced by 90% from CPCB-II limits in the power band 56 < kW ≤ 560. Obvious technology approach adopted by industry to meet this requirement is the introduction of CRDI fuel injection system & DOC+SCR+ASC aftertreatment technology, leading to substantial modifications at both engine & genset level. This result into huge development expenditure, high incremental product cost, timelines and increased total cost of ownership. This paper describes the frugal technology approach to keep development cost, product cost, development time to the minimum using electronically governed, high pressure mechanical fuel injection equipment, with DOC+SCR+ASC without any external thermal management strategy while comfortably achieving target CPCB-IV+ emission levels. This integrated approach also helped in completing the entire development in < 12 months. 1D-thermodynamic & 3D-combustion simulation approach was adopted to predict the engine out emissions
Arde, Vasundhara, Juttu, Simachalam, Kadam, Atit, Gothekar, Sanjeev, Karthick, K, Vandana, Suryanarayana, Thipse, S, Kendre, Mahadev
Accelerating EV Thermal Controller Development Using Rapid Control Prototyping on Speedgoat2026-26-06851/16/2026
In the era of Software Defined Vehicles, the complexity and requirements of automotive systems have increased knowingly. EV Thermal management systems have become more complicated while having multiple functions and control strategies within software frameworks. This shift creates new challenges like increased development efforts and long lead time in creating an efficient thermal management system for Electric Vehicles (EV’s) due to battery charging and discharging cycles. For solving these challenges in the early stages of development makes it even more challenging due to the unavailability of key components such as fully developed ECU hardware, High voltage battery pack and the motor. To address this, a novel framework has been designed that combines virtual simulation with physical emulation at the same time, enabling the testing and validation of thermal control strategies without fully matured system and the ECU hardware. The framework uses the Speedgoat QNX machine as the
Chothave, Abhijeet, S, Bharathan, S, Ananth, Gangwar, Adarsh, Khan, Parvej, Gummadi, Gopakishore, Kumar, Dipesh
Engine Compartment Front End Module & Snorkel Placements to Achieve Maximum Volumetric Efficiency2026-26-05881/16/2026
The rising demand for electric vehicles (EVs) has pushed automakers to prioritize visual brand consistency across both EVs and internal combustion engine (ICE) vehicles. A main design factor which is influenced by this trend is the front grille. In order to achieve uniform aesthetic looks, passenger car manufacturers often reduce the front grille openings and limit airflow. This closed grille style is common in electric vehicle. However, this creates challenges for internal combustion engine (ICE) vehicles with snorkel-type air intake systems, leading to reduced airflow and higher temperatures in the engine bay and intake air which eventually gets sucked in the engine resulting in low volumetric efficiency. Maintaining a cooler intake air is vital for ICE performance. Adjusting snorkel position and airflow patterns in low temperature zones ensures the engine receives air at low temperatures. This improves the combustion efficiency, throttle response and eventually it reduces the risk
Sonone, Sagar Dinesh, Singh, Nil Kanth, Kolhe, Vivek M, Kulkarni, Chaitanya, Malekar, Hemant A
Multiphysics Analysis of Heat Sink Designs for Efficient Thermal Performance in Power Electronics Systems2026-26-04461/16/2026
The thermal management capability of power electronic (PE) systems has a critical impact on the performance and efficiency of electric, fuel cell, or hybrid vehicles. Bus bars, high resistance sensor devices, semiconductor switches, power capacitors are the primary components, which make a major contribution in total heat generation in electrical drive unit. As PE packaging sizes are projected to become smaller, the challenge of managing increased heat dissipation becomes more critical. This paper numerically compares six different cooling strategies to determine the best possible thermal management scenario. A coupled physics co-simulation framework is used to analyze a 35W motor inverter integrated with water cooled heat sink. A multi-physics finite element model, integrating fluid, electrical, and thermal fields, is employed to analyze heat generation within the PE system and the associated cooling mechanisms. The power losses from the inverter system are dynamically computed in 1-D
Singh, Praveen Kumar, Natarajan, Nesamani, Murali, Sariki
Cabin Modelling Approach in 1D Simulation for Studying the Impact of Partial Recirculation in Warmup for BEV at Extreme Cold Ambient Conditions2026-26-04501/16/2026
The inclusion of the cabin in HVAC simulations gained more importance with the introduction of BEV’s. Thermal management and efficiency being in the forefront, exploration for the possible opportunities to reduce the energy consumption for meeting the comfort of passengers gained importance. The energy consumed by the Electric coolant or air heaters for heating the cabin at extreme cold ambient temperatures to deliver similar comfort to that of an ICE version is 2 to 3 times that of the energy required for cooling the cabin in a high ambient condition. Even during the sizing of HVAC system, if traditional method of ambient or fresh air conditions is considered for calculating the requirements, the result is we would require a product which will have unrealistic performance demand. Hence to explore different possibilities for studying the system, usage of recirculation air was considered as one of the options. This paper talks about the approach followed in creating the cabin model in
Veerla, Eswar, Subramanian, Karthik
Quantifying the Energy Consumption of HVAC Operation and Its Impact on the Range of Electric Buses Across Diverse Climatic Conditions2026-26-02041/16/2026
Electric buses (e-buses) are essential to sustainable public transport, but their real-world efficiency and range are heavily affected by auxiliary systems, particularly the Heating, Ventilation, and Air Conditioning (HVAC) system. This study investigates how ambient temperature variations and HVAC loads influence energy consumption, range, and efficiency in e-buses operating under diverse climatic conditions. The methodology combines field data collection from urban e-buses across seasons—including extreme summer and winter—with controlled laboratory testing. Field measurements included ambient temperature, HVAC demand, vehicle speed, state of charge (SOC) variation, and energy consumption. These inputs were used to develop real-world duty cycles, replicating actual thermal loads, passenger profiles, idling periods, and driving patterns. In the laboratory, these cycles were simulated using a chassis dynamometer and environmental chamber, with HVAC systems tested at controlled ambient
Vishe, Prashant, Dalela, Saurabh, Saraswat, Shubham, Joshi, Madhusudan
Thermal Management and Engine Calibration Strategies for Enhanced Passive DPF Regeneration in CEV Stage V CI Engines2026-26-01411/16/2026
Meeting the stringent emissions norms of CEV stage V for medium BMEP engines, CI engines present significant challenges. These stringent norms call for a highly efficient DPF. With the increasing demands for high-performance DPFs, the issue of soot accumulation and cleaning presents significant hurdles for DPF longevity. This paper explores the potential of passive DPF regeneration, which leverages naturally occurring exhaust gas conditions to oxidize accumulated soot, offering a promising approach to minimize fuel penalty and system complexity compared to active regeneration methods. The study investigates engine calibration techniques aimed at enhancing passive regeneration performance, emphasizing the optimization of thermal management strategies to sustain DPF temperatures within the passive regeneration range. Furthermore, the paper aims to expand the applicability of passive regeneration across diverse engine loads common in off-highway applications with effective passive
Saxena, Harshit, Gandhi, Naresh, Lokare, Prasad, Shinde, Prashant, Patil, Ajit, Raut, Ashish
Thermal Management Techniques to Overcome Overheating in Printed Circuit Boards2026-26-03771/16/2026
Nowadays, Printed Circuit Board (PCB) design is facing critical challenges like high heat dissipation, increased cost, densely populated components and reduced life span. In view of the above, present study is focused on temperature prediction, thermal management, and optimization of component allocation (e.g. mosfet) in PCB. Heat flow occurring from traces to different copper layers in the PCB can cause adverse effects such as thermal run away/PCB warpage. Here, transient thermal analysis is carried out in an in-house developed PCB which is placed inside a sheet metal enclosure. Initially, thermal prediction to explore thermal regimes in the PCB is performed with the help of a commercially available software Altair Simlab ElectroFlo 2024.1. Temperature across all the components of the PCB as well as at the enclosure is simulated which is found to be beneficial in identifying the critical hotspots. In addition to the above, thermal measurements are performed in the lab with the help of
Rajasekharan, Jayakrishnan, ML, Sankar, Prasad, Suryanarayana
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