Browse Topic: Thermodynamics

Items (5,893)
This paper explores the adaptability and reliability testing methods of electric vehicles under the unique high-temperature and high-humidity climate conditions in Southeast Asia. The focus of the research here is on five key performance evaluation contents, namely reliability driving test, charging performance test, range assessment, air conditioning cooling efficiency, and in-vehicle air quality monitoring. Relying on a meticulously designed experimental plan, standardized testing procedures, and comprehensive data analysis, this paper assesses the performance of electric vehicles under extreme environmental conditions. The research results show that the climate in Southeast Asia poses significant challenges to the battery systems, powertrains, and thermal management systems of electric vehicles. Based on empirical results, some improvement suggestions are made to support the deployment and application of electric vehicles in this region.
Wang, WeijieDeng, TianhaoWu, YilongZang, Haonan
In recent decades, interest in alternative fuels has grown exponentially. Hydrogen has been researched as total or partial substitutes for gasoline in light vehicles, showing great potential. However, this fuel has unique characteristics and properties that can bring improvements or limitations in engine performance. Therefore, a quick analysis of the pressure and HRR curve can highlight changes in combustion and performance. To this end, the aim of this work is to develop a visual interface generated by MATLAB capable of showing the performance parameters of a spark ignition engine when using hydrogen as fuel, initially. This graphic interface is supported with a zero-dimensional model based on the Wiebe function and Woschni correlation to estimating the pressure and HRR values. The interface is designed to receive operating conditions and geometry of the engine, as well as combustion angles. From the information entered, it is possible to visualize mass fraction burned, heat transfer
Rincon, Alvaro Ferney AlgarraAlvarez, Carlos Eduardo CastillaOliveira Notório Ribeiro, Jéssica
System robustness and performance are essential considerations in controller design to ensure reference tracking, disturbance rejection, and resilience to modeling uncertainties. However, guaranteeing that the system operates within safe bounds becomes a priority in safety-critical applications, even if performance must be compromised temporarily. One prominent example is the thermal management of lithium-ion battery packs, where temperature must be strictly controlled to prevent degradation and avoid hazardous thermal runaway events. In these systems, temperature constraints must consistently be enforced, regardless of external disturbances or control errors. Traditional strategies, such as Model Predictive Control (MPC), can explicitly handle such constraints but often require solving high-dimensional optimization problems, making real-time implementation computationally demanding. To overcome these limitations, this study investigates the use of a Constraint Enforcement strategy to
Ebner, Eric RossiniFernandes, Lucas PasqualLeal, Gustavo NobreNeto, Cyro AlbuquerqueLeonardi, Fabrizio
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Apaza, Jerson Bequer UrdayPradelle, FlorianBraga, Sergio LealSánchez, Fernando ZegarraGuzman, Juan Jose Milon
In automotive applications a power electronic converter is used for energy conversion between battery and electrical machine. For high performance drives a lightweight design is demanded. Additionally, a higher efficiency of the inverter results in lower cooling requirements but is often achieved by increasing component weight. Hence, thermal modeling of the components and their interactions is essential to determine the best compromise between weight, efficiency and cooling requirements. In traction inverters the DC-link capacitors, power modules, high voltage electrical connections and low voltage devices dissipate power. In this paper the focus is on the thermal modeling of the DC-link capacitor, power modules and high voltage electrical connections and their system, as the performance of the inverter is defined by these components. The thermal models are derived based on physical properties and geometries. First, the DC-link capacitor thermal model is presented and considers the
Blaschke, Wolfgang MaximilianMengoni, LeonardPflüger, RobinKulzer, André Casal
Virtual reality (VR), Augmented Reality (AR) and Mixed reality (MR) are advanced engineering techniques that coalesces physical and digital world to showcase better perceiving. There are various complex physics which may not be feasible to visualize using conventional post processing methods. Various industrial experts are already exploring implementation of VR for product development. Traditional computational power is improving day-by-day with new additional features to reduce the discrepancy between test and CFD. There has been an increase in demand to replace actual tests with accurate simulation approaches. Post processing and data analysis are key to understand complex physics and resolving critical failure modes. Analysts spend a considerable amount of time analyzing results and provide directions, design changes and recommendations. There is a scope to utilize advanced features of VR, AR and MR in CFD post process to find out the root cause of any failures occurred with
Savitha, BhuduriSharma, Sachin
Traditionally, off-highway vehicles like tractors and construction machinery have relied on hydraulic, viscous, or fixed fans to meet the cooling demands of diesel engines. These fans draw power from the engine, impacting fuel consumption and contributing to noise levels that affect operator comfort. Recently, the adoption of electric fans in off-highway applications has increased due to their energy efficiency, lower noise, and flexible design. Electric fans can cool various components, such as radiators and condensers, and can be positioned for optimal performance. They are easily selected from established supplier catalogs based on application requirements like machine voltage, fan size, and type. This study explores various fan arrangements, including pusher and puller types, and multiple electrical fan banking based on cooler zones to improve cooling system performance without changing cooler size or specifications. A mathematical flow model was developed for both setups: the
Durairaj, RenganathanDewangan, NitinAnand, KetanBhujbale, Sagar
In the electrical machines, detrimental effects resulted often due to the overheating, such as insulation material degradation, demagnetization of the magnet and increased Joule losses which result in decreased lifetime, and reduced efficiency of the motor. Hence, by effective cooling methods, it is vital to optimize the reliability and performance of the electric motors and to reduce the maintenance and operating costs. This study brings the analysis capability of CFD for the air-cooling of an Electric-Motor (E-Motor) powering on Deere Equipment's. With the aggressive focus on electrification in agriculture domain and based on industry needs of tackling rising global warming, there is an increasing need of CFD modeling to perform virtual simulations of the E-Motors to determine the viability of the designs and their performance capabilities. The thermal predictions are extremely vital as they have tremendous impact on the design, spacing and sizes of these motors.
Singh, BhuvaneshwarTirumala, BhaskarBadgujar, SwapnilHK, Shashikiran
An agricultural tractor comprises a tightly packed underhood compartment, which poses distinct challenges in managing airflow through its heat exchangers. The intricate design results in uneven airflow patterns, as the fan-driven system draws air from the front, top, and side openings. This work presents a methodology to measure the cooling airflow volume in the tractor and establishing a correlation between test airflow and CFD simulated airflow values. A handheld anemometer and 3x3 matrix type anemometer used for airflow measurement. Measurements were taken at front and back of heat exchanger. It was concluded that, measuring airflow through the heat exchanger with a matrix-type anemometer positioned behind it can enhance the correlation with CFD results to 84%.
A, BoopalshanmugamGanesan, ThanigaivelReddy, LakkuSateesh, TadiGopinathan, Nagarajan
The average product development cycle spans 3-5 years, involving extensive virtual and physical testing of the machine. Advances in simulation tools have significantly enhanced our ability to identify product solutions early in the design phase. Tools like 1D KULI and Creo Flow Analysis (CFA) offer faster solutions in less time, thereby accelerating the product development cycle. Cooling systems are crucial components of off-highway tractor machines, directly affecting engine efficiency and overall machine functionality. An optimized cooling system ensures the engine operates within safe temperature ranges, preventing overheating and potential damage. Thus, designing an effective cooling system is a vital aspect of machine engineering. 3D Computational Fluid Dynamics (CFD) simulations are essential for evaluating cooling system performance. These high-fidelity simulations provide detailed insights into fluid flow and heat transfer, enabling engineers to predict and enhance cooling
Ukey, SnehalTirumala, BhaskarNukala, Ramakrishna
Electrification applications are increasingly moving towards higher voltage systems to enable greater power delivery and faster battery charging. This trend is particularly evident in the shift from 400V to 800V systems, which offers several benefits and poses unique technical challenges. Higher voltage systems reduce current flow, minimizing energy losses, and improving overall efficiency. This is crucial for applications like electric vehicles and off-highway machinery, where efficient power management is essential. One of the primary benefits of increasing the DC link voltage beyond the 400V is the ability to support higher power levels. Additionally, higher voltage systems can reduce the size and weight of power components, contributing to more compact and lightweight designs. However, transitioning to 800V systems introduces several technical challenges in power electronics design. Key components such as power components (IGBT, MOSFET etc.) must be optimized to handle higher
Hatkar, Chetan ManoharPipaliya, Akash
Hydrogen PFI engines face abnormal combustion issues, especially during transient operation. The air-to-fuel ratio and trapped exhaust gas significantly affect combustion stability and NOx emissions, requiring continuous monitoring. Real-time estimation of the trapped gas composition and thermodynamic state is therefore crucial but challenging. This work introduces a real-time, physics-based Multi-Input-Multi-Output (MIMO) model for accurately estimating trapped air and exhaust gas mass at the intake valve closing (IVC) event. In detail, the estimation model makes use of dynamic in-cylinder and exhaust pressure measurements to accurately model mass flows and heat exchange equations with 0.5 CAD resolution. This allows extremely high fidelity when modelling the physical properties of the various chemical species along the engine cycle. Moreover, the model calibration appears only in the form of two coefficients implemented on a lookup table for twelve different operating points
Galli, ClaudioFerrara, GiovanniGrilli, NiccolòBalduzzi, FrancescoRomani, LucaVichi, Giovanni
This numerical study investigates a spark-ignited, two-stroke engine employing uniflow scavenging, flathead cylinder head design, and an exhaust valve system to identify the optimal bore-to-stroke (B/S) ratio for maximizing brake efficiency at fixed displacement. A single-cylinder prototype engine was constructed, and its experimental data validated a 1D GT-SUITE simulation model. This validated model was then utilized to simulate a full-scale, 1.5-liter displacement, horizontally opposed four-cylinder engine with supercharger-assisted boosting, intended for small aircraft propulsion. The simulations explored a range of B/S ratios from undersquare (0.7) to oversquare (1.5), maintaining a consistent brake power output of 60 kW at 3000 rpm and lambda 0.9. Results showed that increasing the B/S ratio enhanced brake efficiency from 26.0% at B/S=0.7 to 27.0% at B/S=1.5, largely due to reduced frictional losses attributed to shorter stroke and lower piston speeds, decreased heat transfer
Zanchin, GuilhermeHausen, RobertoFagundez, Jean LuccaLanzanova, ThompsonMartins, Mario
The growing demand for lightweight, durable, and high-performance materials in industries such as aerospace, automotive, and energy has driven the development and evaluation of thermoset and thermoplastic composites. Within this framework the static and fatigue mechanical behavior of one thermoset material and two thermoplastic composites are investigated in the (-30° +120°C) temperature range, to simulate extreme environmental conditions. The results from the tensile tests show the different mechanical behavior of the investigated materials, while the cyclic test results highlight the significant impact of temperature on structural properties, offering useful insights for their application in temperature-sensitive environments. This research is partially funded by the Italian Ministry of Enterprises and Made in Italy (MIMIT) within the project ”New Generation of Modular Intelligent Oleo-dynamic Pumps with Axial Flux Electric Motors,” submitted under the ”Accordi per l’Innovazione
Chiocca, AndreaSgamma, MicheleFranceschini, AlessandroVestri, Alessiomancini, SimoneBucchi, FrancescoFrendo, FrancescoSquarcini, Raffaele
This study addresses the challenge of reducing the experimental workload involved in characterizing battery cell behavior as a function of state of charge and temperature. Galvanostatic Intermittent Titration Technique tests were carried out in a climate chamber across a wide temperature range, from -20 °C to 70 °C, with 10 °C intervals. The voltage and current response data collected from these tests were used to train several machine learning algorithms. The trained models could then be used to predict the cell voltage response every 5 °C from -15 °C to 55 °C. While the models were experimentally validated at 15 °C, 25 °C, and 35 °C, the predicted voltages across this range contribute to enhancing the characterization process. In particular, the inclusion of these predicted voltage profiles—combined with the experimental data collected every 10 °C from -20 °C to 70 °C—allows for the creation of more accurate lookup tables for the parameters of the equivalent circuit model. These
Giuliano, LucaPeretto, LorenzoCanella, NicholasNefat, Damir
Liquid cooling systems are a widely used method for cooling lithium-ion batteries in modern electric vehicles. Battery thermal plate (BTP) is a key component of the liquid-cooled thermal management system, which regulates battery temperature to prevent thermal runaway and fire accidents. Designing an energy efficient flow pattern with uniform velocity and temperature distribution is a major challenge for the BTP. In this paper, the effect of flow patterns in cooling performance of the BTP is examined. Battery temperature can be efficiently controlled by varying direction, number of flow channels and structure of the BTP. Complex flow pattern networks are modeled and compared based on the computational fluid dynamics results. The channel flow resistance, pressure drop, and temperature distribution are key parameters which are evaluated for varying mass flow rate conditions. From this study, the flow pattern which satisfies the temperature requirement and has 10% less pumping power
K, MuthukrishnanS, SaikrishnaK, KeshavbalajeGutte, Ashish
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