Browse Topic: Thermodynamics

Items (5,764)

Optimization method of phase change energy storage device for electric vehicle batteries based on numerical simulation

2025-01-8603To be published on 04/01/2025

Phase change energy storage devices are extensively utilized in latent heat thermal energy storage and hold significant potential for application in the thermal management of automotive batteries. By harnessing the high-density energy storage capabilities of phase change materials to absorb heat released by the batteries, followed by timely release and utilization, there is a substantial improvement in energy efficiency. This approach aligns with the objective of promoting low-carbon environmental protection and presents an opportunity to enhance the operational performance and energy utilization efficiency of electric vehicle batteries in low-temperature conditions. However, the thermal conductivity of medium and low temperature phase change materials is poor, leading to its inefficient utilization. This paper focuses on optimizing the structure of a phase change heat exchanger in a phase change energy storage device to improve its performance. A basic design of the phase change heat

Zhang, Haonan, Sun, Mingzhe, Zheng, Haoyun, Zhang, Tianming

Experimental Analysis of Piston Surface Temperature in a Heavy Duty Compression Ignition Engine

2025-01-8383To be published on 04/01/2025

The heat transfer processes occurring in a compression ignition engine are complex, especially considering flame-wall interaction on the piston crown from impinging jets. To study the heat flux occurring on the piston in a heavy-duty diesel engine, a piston was instrumented with fifteen thermocouples and a wireless telemetry system. Eight of the thermocouples are high speed surface thermocouples placed primarily in regions with significant flame-wall interaction, providing crank-resolved surface temperature data. This work presents the first experimental datasets collected with this instrumented piston, describing in detail the thermocouple location selection process as well as data processing and uncertainty quantification for the high-speed surface thermocouples with a particular emphasis on cyclic variability and sensor-to-sensor variability. With this methodology established, data from this piston can be used for modeling and simulation studies as well as for studying the impact of

Gainey, Brian, Datar, Aditya, Ravikumar, Avinash, Bhatt, Ankur, Vedpathak, Kunal, Kumar, Mohit, Gingrich, Eric, Tess, Michael, Korivi, Vamshi, Lawler, Benjamin

3D CHT Simulation of Oil-Cooled Electric Motors: A Comparative Study of Standard and Paperless Designs

2025-01-8181To be published on 04/01/2025

Conjugate heat transfer (CHT) analysis of cooling in an electric motor, featuring both the standard and the paperless stator designs, was conducted using the CFD package Simerics-MP+ to assess the predictive accuracy of the numerical simulations. The condition investigated involved the motor running at 14,000 RPM. The high rotor speed was modeled using a novel hybrid approach for mesh rotation to make the problem more tractable. The two immiscible fluids, oil and air were modeled using the interface capturing, volume of fluid (VOF) method. The traditional CHT approach is computationally expensive for electric motor cooling applications due to the heat transfer time scale differences between the fluid and the solid. Temperature changes in solids occur over a much slower time scale owning to their higher thermal inertia compared to fluids. Therefore, we model the fluid and solid domains separately and use a mixed-time scale approach to exchange the heat transfer data between them. The

Varghese, Joel, Srinivasan, Chiranth, Chen, Yawei, Bhunia, Srijohn, Schlautman, Jeff

Model-Predictive Control for Heat Pump-Based Battery Thermal Management in Off-Road Autonomous Electrified Vehicles During Transient Operation

2025-01-8184To be published on 04/01/2025

The shift towards hybrid and electric powertrains in off-road vehicles aims to enhance mobility, extend range, and improve energy efficiency. However, heat pump-based thermal management systems in these vehicles continue to consume significant energy, impacting overall range and efficiency. Effective thermal management is essential for maintaining battery performance and safety, particularly in extreme conditions. Although high-fidelity models can capture the complex dynamics of heat pumps, real-time control within model-based optimization frameworks often depends on simplified models, which can degrade system performance. To address this, we propose a novel data-driven grey box control-oriented model (COM) that accurately represents the thermal dynamics of a vapor-compression refrigeration-based heat pump system. This COM is integrated into a model-predictive control (MPC) framework, optimizing thermal management during transient and burst-power operations of the battery pack. We

Sundar, Anirudh, Ghate, Atharva, Zhu, Qilun, Prucka, Robert, Ruan, Yeefeng, Figueroa-Santos, Miriam, Barron, Morgan

A Conjugate Heat Transfer Numerical Framework Applied to Energy-Assisted Ignition of Jet Fuel in a Rapid Compression Machine

2025-01-8352To be published on 04/01/2025

Airborne compression ignition engines operating with aviation fuels are a promising option for reducing fuel consumption and increasing the range of hybrid-electric aircraft. However, the consistent ignition of Jet fuels at high-altitude conditions can be challenging. A potential solution to this problem is to ignite the fuel sprays by means of a glow-plug-based ignition assistant (IA) device. The interaction between the IA and the spray, and the subsequent combustion event result in thermal cycles that can significantly affect the IA's durability. Therefore, designing an efficient and durable IA requires detailed understanding of the influence that the IA temperature and insertion depth have on the complex physics of fuel-air mixture ignition and flame propagation. The objective of this study is to design a conjugate heat transfer (CHT) modeling framework that can numerically replicate F-24 Jet fuel spray ignition using a glow-plugbased IA device in a rapid compression machine (RCM

Oruganti, Surya Kaundinya, Lien, Hao-Pin, Torelli, Roberto, Motily, Austen, Lee, Tonghun, Kim, Kenneth, Mayhew, Eric, Kweon, Chol-Bum

Advanced Engine Cooling System for a Gas-Engine Vehicle, Part III: State Feedback Control System Design

2025-01-8161To be published on 04/01/2025

This paper presents an advanced control system design for an engine cooling system in an internal combustion engine (ICE) vehicle. Building upon our previous work, we have derived models for crucial temperatures within the engine, including combustion wall temperature, coolant-out temperature, block temperature, as well as temperatures in external components such as heat exchangers and radiator. To accurately predict these temperatures in a rapid manner, we have utilized a lumped parameter concept with a mean-value approach. This approach allows for precise temperature estimation while maintaining computational efficiency. Given the complexity of the cooling system, we have proposed a linear time-varying (LTV) model predictive control (MPC) system to regulate the temperatures. This control system linearizes the model at each time step and applies linear MPC over the control and prediction horizons. By doing so, we effectively control the highly nonlinear and time-delayed system

Chang, Insu, Sun, Min, Edwards, David

Impact of Thermal and Electrical Dissimilarities on Battery Module Aging

2025-01-8173To be published on 04/01/2025

Battery cell aging and loss of capacity are some of the many challenges facing the widespread implementation of electrification in mobility. One of the factors contributing to cell aging is the dissimilarities of individual cells connected in a module. This paper reports the results of several aging experiments using a mini-module consisting of seven 18.2 Ah 21700 Lithium-ion battery cells connected in parallel. The aging cycle comprised a constant current-constant voltage charge cycle at a 0.7C C-rate, followed by a 0.2C constant current discharge, spanning the useful voltage range from minimum to maximum according to the cell manufacturer. Charge and discharge events were separated by one-hour rest periods and were repeated for four weeks. Weekly reference performance tests were executed to measure static and pulse power capacity as well as discharge impedance. All diagnostics were normalized with respect to their starting numbers to achieve a percentage change over time. Both

Swarts, Andre, Salvi, Swapnil S., Juarez Robles, Daniel

Analysis of Coolant Flowing and Heat Transfer Performance in High Voltage Heater System

2025-01-8194To be published on 04/01/2025

A method for performance calculation and experimental method of a high voltage heater system in electric vehicles is proposed. This system is critical for the thermal management of electric vehicle batteries, especially in low-temperature environments. It provides essential heating support to maintain optimal battery performance and safety, thereby improving overall efficiency and reliability.Firstly, heater outlet temperature and pressure drop of the heater are used as metrics to compare simulation results with experimental data, thereby validating the established model. Then, simulations are performed on two heater flow channel configurations: a cavity flow channel and a cooling fin flow channel. It is observed that the latter significantly reduces the heating plate temperature. This reduction enhances the protection of heating elements and extends their operational lifespan, demonstrating the advantages of incorporating cooling fins into the flow channel structure. The optimization

Gong, Ming, Wang, Xihui, Wang, Dongdong, Shangguan, Wen-Bin

Thermal Simulation of Ball Bearing in Electric Drive Unit: A CFD Study Using Volume of Fluid and Mixed Timescale Coupled Conjugate Heat Transfer Analysis

2025-01-8178To be published on 04/01/2025

The drive unit of electric vehicles is a complex system consisting of an electric motor and a gear train, which work together to provide the necessary power for vehicle propulsion. One essential component within this system is the ball bearing, which supports the rotating components such as gears and shafts. This study focuses on the thermal simulation of a ball bearing within the drive unit conducted using the Volume of Fluid (VOF) method coupled with mixed timescale Conjugate Heat Transfer (CHT) in Simerics-MP+ to reduce the computational time while ensuring accuracy in the analysis. The Computational Fluid Dynamics (CFD) approach considers the geometrical details and clearances of the inner race, outer race, cage, and ball within the ball bearing. By accounting for the relative motions between these components, it can accurately model the film formation of the lubricating oil and its impact on heat removal from the bearing. The simulations are conducted at two different shaft speeds

Ballani, Abhishek, Motin, Abdul, DHAR, Sujan, Ganamet, Alain, Maiti, Dipak, Ranganathan, Raj, Pandey, Ashutosh

Thermal Insulation Tiles and Sheets Based on Intergration of Recycled Plastic Waste Fibres and Epoxy Resin

2025-01-8325To be published on 04/01/2025

Plastic waste has risen to be one of the most concerning and endangering pollutants to the environment and nature in the past few years, making its effective management and reduction a major domain of focus among researchers and industrialists. This comparative study is an attempt to utilize recycled Polyethylene Terephthalate (rPET) fibres combined with Epoxy Resin in various combinations, to provide effective and low-cost insulation in moderate to low requirements. The above-mentioned components serve as viable insulators with their thermal conductivities ranging from 0.2W/mK to 0.3W/mK and 0.15W/mK to 0.35W/mK respectively. Moisture resistance of both materials and temperature resistance of Epoxy resins ranging from 120°C to 150°C (depending upon the grade of Epoxy used) indicates good stability in harsh external operating environments. While epoxy resins are not inherently flame retardants, additives are introduced for this purpose to render the composite safer to use. Moreover

purihella, Sri Sai Krishna, Pali, Harveer Singh, Kumar, Piyush, Sharma, Ved

Knock Assessment in Wankel Rotary Engine Adopting Low Octane Rating Fuels

2025-01-8452To be published on 04/01/2025

Series hybrid vehicles, equipped with internal combustion range extenders, are a promising solution for carbon-free transportation. In this application, zero net carbon emissions can be achieved only using renewable fuels. Fischer-Tropsch-derived e-gasolines allow for high energy density and safe fuels. However, Fischer-Tropsch fuels must undergo several processing stages to reach current engine-grade octane ratings, negatively affecting the synthesis's profitability and energy efficiency. Gasoline engine technologies capable of operating with low-octane fuels could allow the adoption of unprocessed Fischer-Tropsch gasoline. The rotary Wankel engine design suits range extenders thanks to its high power-to-size ratio. In this study, the knocking tendency of homogenous charge spark-ignition rotary Wankel engines is numerically assessed through Chemkin-Pro spark-ignition engine zonal model for knock assessment. Rotary Wankel engines are modeled by providing the corresponding time

Brunialti, Sirio, Vorraro, Giovanni, Turner, James, Sarathy, Mani

Modeling and Simulation analysis of an electric vehicle in normal and hot ambient conditions: energy consumption and driving range

2025-01-8151To be published on 04/01/2025

With better performance and usage of clean and renewable energy, electric vehicles have ushered in more and more consumers’ favor nowadays. However, insufficient driving range especially in hot and cold ambient conditions still greatly restricts the extensive application of electric vehicles. This paper presents a methodology of establishing mechanics-electricity-thermodynamics coupled full vehicle model in AMESim to investigate the energy consumption and driving range of an electric vehicle in normal and hot ambient conditions. Full vehicle energy consumption test was carried out in the climate chamber to check the accuracy of simulation results. Firstly, basic framework of the full vehicle model established in AMESim was introduced. Next, modeling details of sub-systems including vehicle dynamic system, electrical system, coolant circuit system, air-conditioning system and control strategy were illustrated. Then, full vehicle energy consumption tests were carried out in 23℃ and 38

ZHOU, Shuai, Liu, Huaiju, YU, Huili, Yan, Xu, Yan, Junjie

Numerical Comparison of TPMS Structures for the Design of an Automotive Engine Oil Cooler

2025-01-8155To be published on 04/01/2025

Triply Periodic Minimal Surfaces (TPMS) structures offer the possibility of reinventing structural parts and heat exchangers to obtain higher functional efficiency and lighter or even multi-functional components. As crescent global climate concern has led to increasingly stringent emissions regulations, the adoption of TPMS represents a resourceful tool for OEMs to downsize and lighten mechanical parts, thereby reducing the overall vehicle’s weight and fuel consumption. In particular, TPMS structures are gaining growing interest in the heat exchanger field as their morphology allows them to naturally house two separate fluids, thus allowing heat transfer without mixing. Moreover, TPMS-based heat exchanger can provide countless possible design configurations. These structures are obtained by the periodic repetitions in the three spatial dimensions of a specific unit cell with defined dimensions and wall thickness. By tuning their characteristic parameters, the structure can be tailored

Torri, Federico, Berni, Fabio, Martoccia, Lorenzo, Marini, Alessandro, Merulla, Andrea, Giacalone, Mauro, Colombini, Giulia

Research on the Thermal Performance of Thick Film Heater for Electric Vehicle Battery

2025-01-8154To be published on 04/01/2025

The life of power battery and its discharge efficiency in electric cars will be significantly reduced in a low temperature environment. Therefore, in order to ensure its working mileage and safety, heating the power battery is required. Heat pump air conditioners and PTC-based onboard heaters are usually way to heat the power battery under lower temperature so far. In low temperature environment, due to the lower heating efficiency of the heat pump air conditioner, onboard heaters are widely used in electric cars. A specific thick film heater(TFH) for electric vehicles is investigaed in this study, and its three dimensional heat tansfer analysis model is established. The heat transfer and fluid performace of the TFH is analied using a computational fluid dynamics software. The performance of TFH is measured on a test bench, and the measured data is used to validate the developed model. Using the established model, the heating efficiency of TFH is studied for different inlet

Guan, Wenzhe, Guo, Yiming, Wu, Xiaoyong, Wang, Dongdong, Shangguan, Wen-Bin

Design of an Air-Liquid Coupled Thermal Management System for Battery Packs in Energy Storage Cabinets

2025-01-8168To be published on 04/01/2025

Efficient thermal management is critical for ensuring the performance and safety of large-capacity battery packs. Traditional air or liquid cooling methods often fail to provide sufficient cooling and to maintain uniform temperature distribution. To address these limitations, a novel hybrid air-liquid cooling system was developed in this study. A 3D model of the proposed cooling structure was constructed. Heat transfer and fluid flow resistance were analyzed using computational fluid dynamics (CFD) simulations based on the developed model. The model was validated through experimental measurements. These included discharge temperature rise measurements on individual battery cells and flow resistance tests on the liquid cooling plate. The thermal performance of the air-liquid hybrid cooling system was evaluated at various discharge rates and compared with only air or liquid cooling methods. Results indicated that the hybrid cooling system significantly enhanced heat dissipation. At a

Li, Hao, Guo, Yiming, Zhou, Fupeng, Li, Kunyuan, Shangguan, Wen-Bin

Comprehensive Prediction of Deposit Formation in SCR Systems Using Integrated 1D Heat Transfer Model with Empirical Data from 3D CFD Simulations

2025-01-8491To be published on 04/01/2025

Urea-based selective catalytic reduction (SCR) systems are widely used to meet stringent NOx emission standards in industrial diesel engines. However, suboptimal design of the urea-water solution (UWS) mixing pipes in SCR systems can lead to the formation of urea-derived solid deposits, which may adversely affect the system performance and reliability. Although recent advancements in deposit simulation technology using three-dimensional Computational Fluid Dynamics (3D CFD) have significantly improved the performance and compactness of mixing pipes, assessing deposit formation across all operating and environmental conditions remains challenging due to high simulation costs. This study introduces a novel computational method for predicting the formation and temperature of permanent liquid films from UWS injection which are closely related to deposit formation, along with new deposit evaluation criteria based on them. This proposed method integrates a one-dimensional heat transfer model

Sugimoto, Kazuma, Kawabe, Ken

Flame Extinguishing and Heat Transfer in the Combustion Chamber of a Hydrogen Engine

2025-01-8420To be published on 04/01/2025

Conversion to hydrogen of automobile internal combustion engines powered by fuels of petroleum origin is the most important direction for solving environmental, energy and climate problems of modern civilization. A number of researchers (T. Shudo et al., Demuymeck J. et al., B. Sun et al.), based on experimental studies, note the presence of a phenomenon of a significant increase in heat losses in hydrogen engines compared to gasoline engines. This phenomenon is explained by an increase in temperature and speed of movement of the working fluid. In this paper, it is shown that the main reason for the increase in thermal losses is the ability of the hydrogen flame to penetrate the narrow gap between the piston and the engine sleeve. This problem has not been discussed in engine theory before. 3D mathematical modeling of flame penetration and extinguishing processes in the specified gap of a hydrogen engine (D/S=86/86 mm/mm, Ne=60 kW, n=5500 min-1) was carried out. Critical gap sizes for

Kavtaradze, Revaz, Natriashvili, Tamaz, Gladyshev, Sergey

Experimental Analysis of Battery Thermal Management Techniques for Electric Vehicle Lithium-Ion Batteries Using MATLAB Simulink, Simscape, and Stateflow Simulations

2025-01-8165To be published on 04/01/2025

The integration of lithium-ion batteries into electric vehicles represents a significant advancement in the automotive industry. These batteries are widely utilized in energy storage systems. The extended life cycle, low self-discharge rates, high energy density, and eco-friendliness of lithium-ion batteries are well-known. However, Lithium-ion batteries are highly sensitive to temperature, adversely affecting their performance, lifespan, and safety. Therefore, effective thermal management is critical to ensuring optimal operating conditions and mitigating the risk of thermal runaway. To address this, experimental study was conducted on various battery thermal management techniques, including active, passive, and hybrid approaches. These techniques were investigated for their cooling efficiencies under different operating conditions. The study utilized MATLAB Simulink, Simscape, and Stateflow to simulate the electro-thermal behavior of cylindrical lithium-ion battery cells, battery

Thangaraju, Shanmuganathan

Research on heat dissipation of cabinet of electrochemical energy storage system

2025-01-8193To be published on 04/01/2025

When lithium batteries are charged and discharged in electrochemical energy storage systems, significant internal electrochemical reactions occur, generating substantial heat and causing a rise in battery temperature. This can adversely affect battery performance and lifespan, and in severe cases, lead to thermal runaway, threatening the safety of the entire system. Research on the thermal modeling of lithium-ion batteries, accurate description and prediction of temperature rise, and the design of thermal management systems based on numerical heat flow simulations are crucial for ensuring safe and reliable battery operations. These efforts are vital for advancing new energy technologies. However, most existing research on heat dissipation in energy storage systems focuses solely on single air-cooled or liquid-cooled systems, which often have simple structures and poor heat dissipation effects. Based on the actual size of an energy storage products, this thesis establishes a

Chen, Jianxiang, Li, Liping, Zhou, Fupeng, Li, Chuncheng, Shangguan, Wen-Bin

Biobased Phase Change Material for Electric Vehicle Battery Thermal Management using Copper Fins: A numerical Investigation

2025-01-8171To be published on 04/01/2025

Electric vehicles (EVs) are gaining popularity due to their zero tailpipe emissions, superior energy efficiency, and sustainable nature. EVs have various limitations, and crucial one is the occurrence of thermal runaway in the battery pack. During charging/discharging of EV battery pack which consists Li-ion cells generates significant amount of heat; thermal runaway in the battery pack happens due to excessive heat accumulation inside the cell because of ineffective cooling of the Li-ion cell/battery pack. It necessitates for the development of an effective EV battery thermal management system. In the present work thermal management of a 26650 Lithium iron phosphate (LFP) cell using natural air cooling, composite biobased phase change material (CBPCM) and its combination with copper fins is numerically investigated using multi-scale multi dimension - Newman, Tiedenann, Gu and Kim (MSMD-NTGK) battery model in Ansys Fluent at an ambient temperature of 306 K. Natural air cooling was

Srivastav, Durgesh, Patil, Nagesh Devidas, Shukla, Pravesh Chandra

Impact of Thermal Gradients on Calorimetry Testing of Battery Cells

2025-01-8175To be published on 04/01/2025

Detailed modeling of battery thermal runaway and propagation often requires a source term that represents the chemical heat release of the cell as a function of temperature. The shape of this heat release trend typically comes from cell testing data. Accelerating rate calorimetry (ARC) tests provide concise information on cell self-heating, since the cell is kept nearly isothermal and adiabatic. Also, compared to differential scanning calorimetry (DSC) tests of battery component materials, it contains all interactions between components. Converting the temperature rise rate data to heat release rate is theoretically very simple, only requiring the heat capacity of the cell. Practically, however, careful analysis is required to avoid artifacts arising from limitations of the test setup. This study uses a simple one-dimensional transient heat transfer model to illustrate the runaway process inside a cell and describe two error sources present in many ARC tests. As the cell temperature

Vanderwege, Brad, Petersen, Ben

Downsizing 12 volts battery for EV using effective energy management strategies when vehicle is inactive

2025-01-8192To be published on 04/01/2025

On electric vehicle the low voltage (nominal 12 volt) battery serves mostly as an energy storage buffer for supporting features and actuators on the 12 volts power supply network. The power management strategies significantly influences the thermal management of the vehicle especially in power critical states. Within an EV, unlike an internal combustion engine car, as there is no cranking requirement needed to be supported by this battery, it presents a significant opportunity for downsizing. This can save from 10 kg-15 kg which could add up to 1 mile of range in combined cycle. In a premium car there are a significant number of features which inhibits the car to go into “deep sleep” and hence remains on a “stand-by” mode of operation. During this period of stand-by the low voltage energy storage system need to be sized for up to 0.4 W of continuous power drain. To sustain longer periods of stand-by mode the low voltage battery needs to have enough stored energy to maintain the

Dutta, Nilabza, Overs, Sheldon

Temperature control of proton exchange membrane fuel cell thermal management system based on fuzzy PID

2025-01-8187To be published on 04/01/2025

The temperature regulation of the fuel cell thermal management system is characterized by slow response speed, system oscillation, and strong coupling, which is prone to problems with unstable temperature control and affects the characteristics of the fuel cell and the lifetime of the electric stack. For a 300kW high-power fuel cell system, to effectively control the flow of the thermal management system to achieve temperature regulation accurately, this paper proposes a fuzzy PID control strategy based on the optimization of the genetic algorithm. By establishing the model of the electric stack and thermal management system, including the core components such as the water pump, radiator, fan, temperature control valve, etc., the response mechanism of the thermal management system and the flow distribution and heat exchange of each component are analyzed. Based on the existing test data and related debugging experience, the basic fuzzy rule system is designed, after which the genetic

Zhang, Yilong, Zhang, Yunqing, Guo, Jun, Wu, Jinglai

Capillary transport analysis in macro-homogeneous diffusion media of PEM fuel cells

2025-01-8546To be published on 04/01/2025

The optimal operation of PEM-type fuel cells relies on a delicate management of multiple water-related processes. Due to the interaction of electrochemistry, two-phase flow and heat transfer in porous media, the complex water transport in porous materials is not yet fully understood. The main liquid water transport mechanisms in porous media are the capillary force, the hydraulic permeation and the gravity effect, alongside phase transition, although capillary transport plays a dominant role. Due to the limited experimental data to validate capillary pressure relationships in porous media, the Leverett approach has been conventionally used to model the liquid water transport in PEM fuel cells. It consists of a polynomial expression for water imbibition in unconsolidated sand packs, derived at largely different physical scale than the hydrophobic diffusion media in PEM fuel cells. Therefore, its phenomenological implementation is highly questionable, and a revision of the capillary

Marra, Carmine, Croci, Federico, Fontanesi, Stefano, Berni, Fabio, D'Adamo, Alessandro

A Comprehensive Study of Gaussian Process-Based Multi-Objective Multi-Fidelity Modeling Techniques and its Applications to Shell and Tube Heat Exchanger Design

2025-01-8646To be published on 04/01/2025

In numerous automotive and industrial applications, efficient heat extraction is crucial to prevent system inefficiencies or catastrophic failures. The design of heat exchangers is inherently complex, involving multiple stages defined by the depth of analysis, number of design variables, and the accuracy of physical models. Designers must navigate the trade-offs between highly accurate yet computationally expensive models and less accurate but computationally cheaper alternatives. Multi-fidelity modeling offers a solution by integrating different fidelity models to deliver precise results at a reduced computational cost. In addition to managing these trade-offs, designers often face multi-objective challenges, where optimizing one aspect may lead to compromises in others. Multi-objective optimization, therefore, becomes essential in balancing these competing objectives to achieve the best overall design. In this context, Gaussian Process-based methods have gained prominence as

Chaudhari, Prathamesh, Tovar, Andres

3D Modeling of Thermal Runaway in Pouch Cells: Effects of Surface Heating and Heating Rates

2025-01-8559To be published on 04/01/2025

Thermal runaway in battery cells presents a critical safety concern, emphasizing the need for a thorough understanding of thermal behavior to enhance battery safety and performance. This study introduces a newly developed AutoLion 3D thermal runaway model, which builds on the earlier AutoLion 1D framework and offers significantly faster computational performance compared to traditional CFD models. The model is validated through simulations of the heat-wait-search mode of the Accelerating Rate Calorimeter (ARC), accurately predicting thermal runaway by matching experimental temperature profiles from peer-reviewed studies. Once validated, the model is employed to investigate the thermal behavior of 3D LFPO cells under controlled heating conditions, applying heat to one or more surfaces at a time while modeling heat transfer from non-heated surfaces. The primary objective is to understand how these localized heating patterns impact temperature profiles, including average core temperatures

Hariharan, Deivanayagam, Gundlapally, Santhosh

Aero acoustic noise prediction of passenger car HVAC by using CFD and validation with test result

2025-01-8629To be published on 04/01/2025

The advancement of automobile industries and latest EV technology demands HVAC design of compact size with less noise ,less power and better cabin comfort. To achieve this, HVAC size has to be reduce and improve air flow by proper HVAC design followed by CFD simulation considering a benchmarking analysis and packaging constraints. Selection of heat exchangers and blower is also done at this stage to meet customer requirement. One of the crucial stage at this point is the prediction of noise at the early stage of HVAC design which helps the designer to anticipate the issue with proper solution. In passenger cars, majorly noise are of two types, aero acoustic as well as vibro acoustic. But for HVAC point of view, aero acoustic noise is more significant due to its severity at higher speed or higher frequency. Since HVAC is mounted inside the cabin, the noise will transfer directly inside cabin and hence the severity of noise or vibration will be higher and the harshness due to this noise

Kame, Shubham, Parayil, Paulson

Experimental and Simulation-Based Characterization of Thermal Runaway in Lithium-Ion Batteries Using Altair SimLab

2025-01-8146To be published on 04/01/2025

Thermal runaway is a critical phenomenon in lithium batteries, characterized by a self-sustaining process due to internal chemical reactions, that is triggered once a certain temperature is reached within the cell. This event is often caused by overheating due to charge and discharge cycles and can lead to fires or explosions, posing a significant safety threat. The aim of this study is to induce thermal runaway on single cells in different ways to characterize the phenomenon and validate the simulation models present in Altair SimLab. The work was conducted in several key phases. Initially, an experimental test was performed in a calorimeter (EV ARC HWS test) to collect temperature data of the Molicel 21700 P45B cell during thermal runaway under adiabatic conditions. These data were used for a simulation on a single cell, allowing a detailed comparison with the experimental results. Subsequently, a test was conducted on a single cell under operational conditions, overheated using a

Giuliano, Luca, Scrimieri, Luigi, Reitano, Simone, Berti Polato, Davide, Ferraris, Alessandro, Comerford, Andrew, Bhatnagar, Saakaar

Control Trajectory Optimization of Electric Vehicle Heat Pump-based Cabin Heating System

2025-01-8144To be published on 04/01/2025

Optimal control of battery electric vehicle thermal management systems is essential for maximizing the driving range in extreme weather conditions. Vehicles equipped with advanced heating, ventilation and air-conditioning (HVAC) systems based on heat pumps with secondary coolant loops are more challenging to control due to actuator redundancy and increased thermal inertia. This paper presents the dynamic programming (DP)-based offline control trajectory optimization of heat pump-based HVAC aimed at maximizing thermal comfort and energy efficiency. Besides deriving benchmark results, the goal of trajectory optimization is to gain insights for practical hierarchical control strategy modifications to further improve real-time controllers’ performance. DP optimizes cabin inlet air temperature and flow rate to set the trade-off between thermal comfort and energy efficiency while considering the nonlinear dynamics and operating limits of HVAC system in addition to typically considered cabin

Cvok, Ivan, Deur, Josko

The Effect of Rotor Notches on Air Gap Heat Transfer Coefficient and Electromagnetic Performance in a Traction Permanent Magnet Synchronous Motor

2025-01-8143To be published on 04/01/2025

This study investigates the impact of various notch geometries, specifically on the outer surface of the rotor of a permanent magnet synchronous motor, on the thermal and electromagnetic (EM) performance. Typical motor cooling methods, such as water jackets or oil spray/impingement, usually target the stator and/or end windings, relying on heat transfer through the airgap to cool the rotor, even though air acts as an insulator. Rotor notches are often used to reduce cogging torque and torque ripple by improving the quality of air gap flux density distribution, leading to a significant increase in motor efficiency and overall performance. The effect of rotor notches on EM performance is well understood, but its impact on the thermal management of the motor, particularly the heat transfer coefficient (HTC) in the airgap, remains unexplored. While existing experimental and analytical work has focused on heat transfer in the airgap for smooth stator and rotor or a slotted stator with a

Zajac, Arthur, De Silva, Buddhika, Lee, Sun, Mistry, Jigar, Nasirizarandi, Reza, Jianu, Ofelia, Kar, Narayan

Modelling of Vehicle Efficiency Through Thermal System Plant and Controls Integration

2025-01-8186To be published on 04/01/2025

Improving the efficiency of Battery Electric Vehicles (BEVs) is crucial for enhancing their range and performance. This paper explores the use of virtual tools to integrate and optimise various systems, with a particular focus on thermal management. The study considers global legislative drive cycles and real-world scenarios, including hot and cold weather conditions, charging cycles, and towing. A virtual vehicle model is developed to include major contributors to range prediction and optimization, such as thermal systems. Key components analysed include high voltage (HV) and low voltage (LV) consumers (compressors, pumps, fans), thermal system performance and behaviour (including cabin climate control), thermal controllers, and thermal plant models. The emergent behaviour resulting from the interaction between hardware and control systems is also examined. The methodology involves co-simulation of hardware and control models, encompassing thermal systems (coolant, refrigerant, cabin

Tourani, Abbas, Price, Christopher, Dutta, Nilabza, Moran Ruiz, Eduardo

Enhancing and Validating Numerical Models for Oil-Jet Cooing on Corrugated Surfaces of Electric Motor Windings

2025-01-8160To be published on 04/01/2025

The U.S. DRIVE Electrical and Electronics Technical Team has set a goal for 2025 to achieve a power density of 33 kW/L for electric vehicle (EV) motors. The increase in motor power density is highly dependent on effective thermal management within the system, making active cooling techniques like oil-jet impingement essential for continued advancements. Due to the time and expense of physical experimentation, numerical simulations have become a preferred method for design testing and optimization. These simulations often simplify the motor-winding surface into a smooth cylinder, overlooking the actual corrugated surface due to windings, thus reducing computational resources and mesh complexity. However, the coil's corrugated surface affects flow turbulence and heat transfer rates. This study utilizes three-dimensional Computational Fluid Dynamics (CFD) simulations to investigate the impingement-cooling of an Automatic Transmission Fluid (ATF) jet on a corrugated surface that replicates

Mutyal, Jayesh Ramesh, Champhekar, Omkar, Gurunadhan, Mohana, Konangi, Santosh, haghnegahdar, Ahmad

Enhancing and Validating Numerical Models for Oil-Jet Cooing on Corrugated Surfaces of Electric Motor Windings

2025-01-8148To be published on 04/01/2025

Mutyal, Jayesh Ramesh, Champhekar, Omkar, Gurunadhan, Mohana, Konangi, Santosh, haghnegahdar, Ahmad

Modeling of Static and Dynamic Mechanical Properties of a Rolling Lobe Air Spring

2025-01-8261To be published on 04/01/2025

To investigate the static and dynamic mechanical properties of air springs and their influencing factors, two models were established in this paper to calculate the static and dynamic mechanical properties of air springs, including a simulation model based on the finite element method and a mathematical calculation model based on thermodynamic theory. First, a performance calculation model for rolling lobe air springs with aluminum tubes was established, which considered the thickness of the bellow and the impact of the inflation and assembly process on the state of the bellow. The static and dynamic mechanical properties of air springs were calculated using this model, including static load-bearing capacity and static/dynamic stiffness. The calculation results showed that both the static characteristics of the air spring under isothermal conditions and the dynamic characteristics under adiabatic conditions were able to be calculated accurately. However, the changes in dynamic

Wang, Sirui, Shangguan, Wen-Bin, Kang, Yingzi, Xia, Zhao, Li, Jianxiang, Yu, Chao

Modeling and Control Strategies of the Thermal Management System for Electric Vehicles

2025-01-8190To be published on 04/01/2025

The electric vehicle thermal management system is a critical sub-systems of electric vehicles, and has a substantial impact on the driving range. The objective of this paper is to optimize the performance of the heat pump air conditioning system, battery, and motor thermal management system by adopting an integrated design. This approach is expected to effectively improve the COP (Coefficient of Performance) of cabin heating. An integrated thermal management system model of the heat pump air conditioning system, battery, and motor thermal management system is established using AMEsim. Key parameters , such as refrigerant temperature, pressure, and flow rate at the outlet of each component of the system are compared with the measured data to verify the correctness of the model established in this paper. Using the established model, the impact of compressor speed on the heating comfort of the cabin under high-temperature conditions in summer was studied, and a control strategy for rapid

Zhang, Min, Li, Liping, Zhou, Jianhua, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin

Material-Combined Vehicle Brake Disc Design for Enhanced Cooling Performance

2025-01-8189To be published on 04/01/2025

The improvement of heat dissipation performance of ventilated brake discs is vital of braking safety. The usual technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC) and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC have better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC have poorer heat capacity yet better thermal stability; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake disc using different friction materials and geometry structures. At the level of material application, Al-MMC and C-SiC friction layer are compared. At the level

Wang, Jiarui, Jia, Qing, Zhao, Civil, Xia, Chao, Yang, Zhigang

Flow and Heat Transfer Performance Analysis of Plate-Fin Heat Exchanger in Electric Vehicles

2025-01-8157To be published on 04/01/2025

In driving condition, the electric drive system of electric vehicles generates significant heat, which increases temperature of the motor, leading to reduced performance and energy loss. To manage the motor temperature and recover energy, a plate-fin heat exchanger (PFHE) is used to facilitate heat exchange between the electric drive system and the vehicle's thermal management system. In this study, Computational Fluid Dynamics (CFD) method was used to investigate the fin structure on thermal flow performance within the PFHE. A CFD simulation model was developed for a local heat exchange unit, considering the generic boundary conditions and temperature-dependent properties of the coolant and oil in the PFHE. The pressure drop and heat transfer rate of the local heat exchange unit were calculated under different boundary conditions, and an empirical formula for the friction factor was derived. The Wilson plot method was applied to separate convective heat transfer resistance from the

Yin, Jintai, Yin, Zhihong, Lu, Xuan, Wang, Mengmeng, Liu, Qian

Research on the Combustion Properties of Gasoline Compression Ignition (GCI) Engine Based on Quasi-Homogeneous Mixture Charge Activity Regulation

2025-01-8409To be published on 04/01/2025

High-octane fuel presents significant potential for enhancing the efficient and clean combustion of small GCI engines. To achieve both efficient and stable combustion during low load scenarios, this study employs the combination of simulation and experimental methodologies. By coordinating the mixing rate and chemical reaction rate, as well as optimizing the equivalent ratio, temperature inhomogeneity and other parameters. It introduces a control strategy termed "oil-gas" control coupling quasi-homogeneous mixture multi-pulse charge activity control. The findings indicate that a quasi-homogeneous mixture can be achieved through single direct injection of gasoline during the suction stroke, with low injection pressure enhancing charge activity and promoting stable combustion. The optimal injection timing is identified at approximately -315 CA ATDC, which corresponds to peak thermal efficiency. The multi-pulse charge activity control strategy effectively regulates the heat release rate

Nie, JinLong, Yi, Yucheng

Assessment of Knock Tendency in a High-Performance Hydrogen-Fuelled Internal Combustion Engine: a Chemistry-Based Numerical Study

2025-01-8429To be published on 04/01/2025

Hydrogen is a viable option to power high-performance internal combustion engines while reducing pollutant emissions thanks to its high lower heating value (LHV) and fast combustion rate. Furthermore, if compared to gasoline, hydrogen is characterized by a higher ignition delay time, which makes it more knock-resistant under the same thermodynamic conditions. In this paper, hydrogen potential as a fuel in a high-performance PFI naturally aspirated engine under stoichiometric conditions and high load regimes is investigated through zero and three-dimensional simulations. The analyses show that a stoichiometric hydrogen mixture reaches higher pressure and temperature values during compression than both iso-octane and gasoline at the same operating conditions, hence limiting the maximum engine compression ratio to avoid undesired ignitions throughout the combustion process. Additionally, hydrogen low density causes a reduction in terms of trapped energy inside the cylinder. Thus, despite

Madia, Manuel, Vaccari, Marco, Dalseno, Luca, Cicalese, Giuseppe, Corrigan, Daire, Villa, Davide, Fontanesi, Stefano, Breda, Sebastiano

Driver-Centric Direct Current Fast Charging of Electric Vehicles via Energy Optimal Thermal Management

2025-01-8374To be published on 04/01/2025

Charging a battery electric vehicle at extreme temperatures can lead to battery deterioration without proper thermal management. To avoid battery degradation, charging current is generally limited at extreme hot and cold battery temperatures. Splitting the wall power between charging and the thermal management system with the aim of minimizing charging time is a challenging problem especially with the strong thermal coupling with the charging current. Existing research focus on formulating the battery thermal management control problem as a minimum charging time optimal control problem. The current control strategy forces the driver to charge with minimum time and higher charging cost irrespective of their driving schedule. This paper presents a driver-centric DCFC control framework by formulating the power split between thermal management and charging as an optimal control problem with the goal of improving the wall-to-vehicle energy efficiency. Proposed energy-efficient charging

Gupta, Shobhit, Kang, Jun-Mo, Zhu, Yongjie, Lee, Chunhao, Zanardelli, Wesley

An investigation into the surface area-to-volume ratio of Wankel rotary engines and how it affects heat transfer and heat losses within them

2025-01-8357To be published on 04/01/2025

Wankel rotary engines are renowned for having lower efficiency than classic reciprocating en-gines. One of the factors affecting the efficiency is an unfavourable surface area-to-volume ratio given by the particular geometry of the engine, which increases the heat loss during the com-bustion phase. A novel and specific study on this aspect was carried out in this work by imple-menting a general parametric routine in Octave/Matlab. It was able to compute the surface ar-ea-to-volume ratio and execute a sensitivity analysis on specific engine geometrical parameters (e.g. housing width “b”) in order to determine the geometrical configuration with the minimum surface area-to-volume ratio for a given swept volume, compression ratio and K factor (i.e. the ratio between generating radius and eccentricity). The aforementioned procedure was then ap-plied considering the geometry of the Advanced Innovative Engineering 225CS rotary engine. Three virtual geometrical configurations with the same

Vorraro, Giovanni, Turner, James

Comprehensive Vehicle Level Thermal Management Simulation Platform: Development and Applications

2025-01-8149To be published on 04/01/2025

In modern vehicles, effective thermal management is crucial for regulating temperatures across various components and sub-systems, ensuring optimal performance, efficiency, safety, and passenger comfort. As the industry shifts towards reducing carbon emissions, powertrain electrification—encompassing electric and hybrid vehicles—has emerged as a prominent trend. This transition introduces complexities, as the powertrain system must now precisely control the temperatures of not only traditional components but also batteries, power electronics, and motors. Typically, the performance of thermal management systems is evaluated only after the physical prototypes are developed for testing, specially through summer and winter road tests. These development and validations at the later stage of the development process significantly increases development risks and costs. To address these challenges, a comprehensive vehicle level thermal management simulation platform is essential. This platform

Xu, Zheng

Next Gen Automotive Heat Shield with Improved Thermo-Oxidative Properties

2025-01-8152To be published on 04/01/2025

Alpha Engineered Composites’ thin profile textile composite heat shields provide thermal protection through several thermodynamic mechanisms including: radiation reflection; heat spreading; and finally heat transfer resistance. Typical under the hood automotive applications require heat shield average operational temperature up to 225ºC, but newer internal combustion engines are being designed for higher operational temperatures to: increase efficiency through higher compression cycle ratios and lean burning; boost power through turbocharging; increase energy density; and support advanced emissions controls like EGR that can increase average operational temperature up to 300ºC. Unfortunately, thermo-oxidative degradation mechanisms negatively impact the polymer structural adhesive within a heat shield textile composite and degrade thermal protection mechanisms. High average operational temperature degradation of traditional versus next generation textile composite heat shields is

Vazquez, Mark

Materials Innovation in Thermal Management: Advancing Aluminum Alloy Technologies for the Next-Generation Electrical Vehicle Battery Cold Plate

2025-01-8162To be published on 04/01/2025

The rapid expansion of the global electric vehicle (EV) market has significantly increased the demand for advanced thermal management solutions. Among these, the battery cold plate is a critical component, essential for maintaining optimal battery temperatures and ensuring efficient operation. As EV batteries increase in size, the thermal management requirements become more complex, necessitating the development of new alloys with enhanced strength and thermal conductivity. These advancements are crucial for the effective dissipation of heat and the ability to withstand the mechanical stresses associated with larger and more powerful batteries. The evolving performance demands of EVs are driving material innovation within the thermal management sector. This study aims to explore global heat exchanger market trends from a materials perspective, focusing on the evolution of alloy mechanical, fatigue, and thermal properties. Specifically, we investigated the transition from traditional

Jalili, Mehdi, Wang PhD, Xu, Razm-poosh, Hadi

Enhancing Disc Brake Performance: Investigating Squeal Noise, Wear, and the Application of Functionally Graded Materials in Brake Rotors

2025-28-0162To be published on 02/07/2025

Disc brakes play a vital role in contemporary automotive braking systems, offering a dependable and effective means of decelerating or halting a vehicle. The disc brake assembly functions by converting the vehicle's kinetic energy into thermal energy through friction. Two key factors that greatly influence the brake assembly's performance and user experience are squeal noise and wear performance. This paper delves into the fundamental mechanisms behind squeal noise and assesses the wear performance of the disc brake assembly. Functionally graded materials (FGMs) are an innovative type of composite material, characterized by gradual variations in composition and structure throughout their volume, leading to changes in properties such as mechanical strength, thermal conductivity, and corrosion resistance. FGMs have emerged as a groundbreaking solution in the design and manufacturing of brake rotors, addressing significant challenges related to thermal stress, wear resistance, and overall

C V, Prasshanth, S, Gurumoorthy, Bhaskara Rao, Lokavarapu, S, Sridhar, S, Badri Narayanan, Kumar, Ajay, Biswas, Sayan

Flow and Heat Transfer Characteristics of microchannel through various nanofluids

2025-28-0024To be published on 02/07/2025

The significant development of power convertors in electrical vehicles demand higher energy consumptions and in turn larger heat generations. To prevent overheating of power convertors a newly designed curved micro channel was designed diamond shaped and triangular cross-sections. The working fluids used are Gc3N4/Water (0.3%), Al2O3/Water (0.3%) nanofluids, and Al2O3-Gc3N4/Water (0.3%) hybrid nanofluid and evaluated the flow and heat transfer characteristics. The heat sink has a cross-sectional area of 80 × 48 mm², and the experimental study was conducted by varying the mass flow rate from 0.1 to 0.5 LPM under a constant heat flux of 50 kW/m². The experimental results revealed that the heat transfer rate and pressure drop for the pentagonal channel increased by 14.2% and 18.9%, respectively, compared to the triangular channel heat sink using hybrid nanofluids. This improvement can be attributed to the secondary flow generated in the oblique finned pentagonal microchannel heat sink

R L, Krupakaran, Petla, Ratna Kamala, Anchupogu, Praveen, Kala, Lakshmi K, Gangula, Vidyasagar Reddy, Tarigonda, Hariprasad

DEVELOPMENT OF COMPOSITE PCM TO ENHANCE HEAT TRANSFER RATE WITH THE ADDITION OF NANOPARTICLES IN THERMAL ENERGY STORAGE

2025-28-0023To be published on 02/07/2025

This paper explores the augmentation of thermal conductivity in paraffin wax through the incorporation of aluminum oxide (Al2O3) and copper oxide (CuO) nanoparticles, leading to the development of composite phase change materials (PCMs). The objective is to enhance heat transfer rates, crucial for various energy storage applications including industrial waste heat recovery and solar thermal energy storage. Differential Scanning Calorimetry (DSC) testing was employed to experimentally investigate the thermal properties of the resulting nanocomposite PCM.The experimental results reveal that the nanocomposite PCM, composed of 96.14% paraffin wax, 2% aluminum oxide, and 1.6% copper oxide, exhibits 1.35 times increase in heat transfer rate compared to conventional paraffin wax. The integration of nanoparticles into the PCM matrix, facilitated by a magnetic stirrer at 50°C for 4 hours, results in uniform distribution and improved grain morphology, as evidenced by SEM images. Moreover, the

Tarigonda, Hariprasad, Kumar, YB Kishore, Kala, Lakshmi K, R L, Krupakaran

Temperature Reduction of Servo Oil in Steering System Using Pulsating Heat Pipe

2025-28-0104To be published on 02/07/2025

There are various steering technologies that are available in market nowadays. Electro- Hydraulic Power Steering (EHPS) is one of them. As hydraulic name is linked to it, the temperature role comes to play. While doing hard cornering the hydraulic oil used to assist the working in steering system gets over heated, due to which oil loses its viscosity and becomes one of the major causes for hard steering in trucks. Also, due to packaging constraints in the truck, a large heat exchanger cannot be used. So, objective of this Thesis is to examine a effective solution which can be compact in design and at the time should be effective to solve this problem. After going through literature analysis, we finalize that the Principal of Pulsating Heat Pipe could be a possible solution. So, for that we design different model based on previous research work in Creo and simulate them in Star CCM+ to finalize the optimality

Saikrishna, VNL, P, Rudresha, Yadav, Satyendra, B, Ruthvika, Vishwasa, Viditha

Cutting-Edge Coating Materials for Dual Fuel Diesel Engines Using Acetylene Aspiration

2025-28-0134To be published on 02/07/2025

A diesel engine with a Yttria Stabilised Zirconium (YSZ) thermal barrier layer (TBL) on the piston crown was used in an experiment. The aim of the investigation was to evaluate the influence of the thermal barrier layer on the efficiency and pollution levels of a diesel engine. The selection of YSZ as the coating material was based on its desirable physical properties including a high coefficient of expansion when exposed to heat, low degree of thermal conductivity, and a high Poisson's number. These characteristics make it a suitable material for use in coatings applied to engine components. In addition to their current research, the scientists are also focusing on identifying sustainable substitutes for conventional petroleum fuels. This is because of the growing concern over environmental impacts and the limited availability of fossil fuel resources. The researchers are seeking new options that are both environmentally friendly and capable of meeting the world's energy demands. By

Sagaya Raj, Gnana, Natarajan, Manikandan, Pasupuleti, Thejasree

Exploring Trapezoidal Salt Gradient Solar Pond Performance A Combined Numerical and Experimental Analysis with and without Reflective Covered Surface

2025-28-0201To be published on 02/07/2025

This study investigates the thermal performance of trapezoidal salt gradient solar ponds through a combined approach of experimental analyses and MATLAB numerical simulations. Salt gradient solar ponds offer a promising solution for sustainable energy generation by harnessing solar radiation and storing it as thermal energy for various applications. However, optimizing their performance is essential to maximize energy efficiency and economic viability. Laboratory experiments were conducted to evaluate the thermal dynamics of trapezoidal salt gradient solar ponds under different conditions, including the presence or absence of a reflective covered surface. These experiments provided valuable empirical data on temperature distribution and heat storage capacity. Additionally, numerical simulations were performed using MATLAB to model the thermal behavior of the ponds and validate the experimental findings. The simulations allowed for a deeper understanding of the underlying mechanisms

J, Vinoth Kumar

Items per page:

1 – 50 of 5764