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Training / Education

FEA Beyond Basics Thermal Analysis

2019-12-16
Finite Element Analysis (FEA) is a powerful and well recognized tool used in the analysis of heat transfer problems. However, FEA can only analyze solid bodies and, by necessity thermal analysis with FEA is limited to conductive heat transfer. The other two types of heat transfer: convection and radiation must by approximated by boundary conditions. Modeling all three mechanisms of heat transfer without arbitrary assumption requires a combined use of FEA and Computational Fluid Dynamics (CFD).
Technical Paper

Low Voltage Powertrain in Light Electric Vehicles

2019-11-21
2019-28-2467
Engineering objective Light Electric Vehicles (LEV) with Li-ion batteries suffer from short battery life and poor efficiency, due to low grade electronics. Battery management systems (BMS) cannot always keep the pack in balance, and after cell voltages drift, capacity of the pack diminishes and some cells may destruct, causing a fire. The paper describes a novel approach to LEV powertrains using parallel connected battery cells & control methodology that keep cells in balance naturally, thereby eliminating BMS and hence safer to use. Li-Ion cells with different chemistries can be used and superior thermal management reduces temperature rise, resulting in longer battery life. Methodology Based on the original invention by the author, the system circuit schematics was designed and simulated using OrCAD PSpice. After obtaining results from the simulation, the first prototype device was constructed and tested in laboratory.
Technical Paper

Thermal Management of Li-Ion Battery Pack using GT-SUITE

2019-11-21
2019-28-2500
Objective It is very important to simulate the battery pack being built to understand its behavior when used in applications especially Electric vehicles (EV). All Li-Ion cells are not the same. They need to be characterized before building any battery pack. Hence modeling the battery pack to simulated its performance in the actual conditions becomes important. Methodology To understand the behavior of cells in the on-field environment, they are tested at various conditions like different rates of charging/discharging, various depth of discharge (DOD), ambient temperature, etc. HPPC test is also performed on cells to derive its RC model equivalent model. GT Suite simulation software is used to model the Li-Ion cell using the testing data. Depending on the pack configuration, the modeled cell is connected in the required series and parallel configuration, to study the battery pack with respect to aging, performance and cooling requirements.
Technical Paper

Electric Vehicle Thermal Management System For Hot Climate Regions

2019-11-21
2019-28-2507
ELECTRIC VEHICLE THERMAL MANAGEMENT SYSTEM FOR HOT CLIMATE REGIONS Rana Tarun*, Yamamoto Yuji, Kumar Ritesh, Bhagatkar Shubhada Pranav Vikas India Private Limited, India Key Words Electric Vehicles (EV); Battery Thermal Management System (BTMS); COP; Electric Vehicle Thermal Management System (EVTMS); BTMS and HVAC System Integration; Thermal System Performance Comparison; Active Liquid Cooling; EV Battery Cooling Research and/or Engineering Questions/Objective Electric Vehicles is the need of time to limit global warming and it is in application at a wide scale in colder or mild climate regions where ambient temperature is limited to mild or moderate level. Its application (Heat pump, CO2) is constrained to cold climates only due to securing better COP for heating function, sacrificing cooling COP of the existing system when operated in Hot Climate Regions, thus limiting its application to nearly half of the automotive user-base.
Technical Paper

Thermal Challenges in Automotive Exhaust System through Heat Shield Insulation

2019-11-21
2019-28-2539
While advanced automotive system assemblies contribute greater value to automotive safety, reliability, emission/noise performance and comfort, they are also generating higher temperatures that can reduce the functionality and reliability of thesystem over time. Thermal management and insulation are extremely important and highly demanding in BSVI, RDE and Non-IC engine operating vehicles. Passenger vehicle and Commercial vehicle exhaust systems are facing multiple challenges such as packaging constraints, weight reduction andthermalmanagement requirements.Frugal engineering is mandatory to develop heat shield in the exhaust system with minimum heat loss. The focus of the paper is to design, develop and validate heat shield products with different variables such as design gap, insulation material, sheet metal thickness and manufacturing processes. 1D and 3D computational simulations are performed with different gaps from 3 mm to 14 mm are considered.
Technical Paper

Replacing twin electric fan radiator with Single fan radiator

2019-11-21
2019-28-2381
Downsizing is one of the crucial activities being performed by every automotive engineering organization. The main aim is to reduce – Weight, CO2 emissions and achieve cost benefit. All this is done without any compromise on performance requirement or rather with optimization of system performance. This paper evaluate one such optimization, where-in radiator assembly with two electric fan is targeted for downsizing for small commercial vehicle application. The present two fan radiator is redesigned with thinner core and use of single fan motor assembly. The performance of the heat exchanger is tested for similar conditions back to back on vehicle and optimized to get the balanced benefit in terms of weight, cooling performance and importantly cost. This all is done without any modification in vehicle interface components except electrical connector for fan. The side members and brackets design is also simplified to achieve maximum weight reduction.
Technical Paper

Coupled Electro-Chemical and Thermal Modeling for Cylindrical Lithium-ion Batteries

2019-11-21
2019-28-2488
The shift over of the automobile sector from the ICE to the electric drives is imminent due to arising global issues of pollution and ever rising pressure on the demand of the natural resources due to lower efficiency of the ICE drives. This has led to uprising of the Lithium-ion batteries, with addition of the burden of living to expectation of clean energy and higher efficiencies. Alongside, with limitation in the availability of the lithium-ion batteries they carry a hefty price tag with them, hence causing huddles in the research. Lack of research leads to failure of batteries and may cause life threatening situations when operating in the vehicle. In order to insight the working of the cylindrical lithium-ion batteries under different driving and environmental conditions a methodology is developed for the coupled electro-chemical and thermal phenomenon. This allows anticipating the behaviour of the battery under different conditions that influence its performance.
Technical Paper

Miniaturized and sleek protective device

2019-11-21
2019-28-2535
A miniaturized and sleek protective device M. Priyanka, Mahindra&Mahindra, India D. Boobala Krishnan*, Mahindra&Mahindra, India T.Vijayan, Mahindra& Mahindra, India Keywords-Fuse, Lightweight. Research and/or Engineering Questions/Objective: Now-a-days there is lot of advancement coming in automobiles. Earlier the electronics were used in engine and engine compartment areas. Now all hydraulics and transmission have been operated by electronics. The role of electronics like sensors, actuators increasing day by day for lifting and moving operations. With increase in electronics circuit, there is complex in wiring harness and packaging space for fuse box is premium Limitations: Limitations of placing other devices. Occupy more space and weight in the vehicle. Packing constraint due to vibration and thermal management issues. Methodology: Two different fuse of same rating can be given in one fuse and we can reduce the wire size.
Training / Education

Introduction to Power Electronics in Automotive Applications

2019-11-04
Modern power electronics (PE) devices and circuits are now in widespread use in automotive and non-automotive applications. The purpose of this course is to give an overall introduction to the key aspects of power electronic circuits, components and design in automotive applications. Topics covered include power semiconductor devices, their characteristics and operation, and their use in power electronics circuits.
Technical Paper

A New Co-Simulation Approach for Tolerance Analysis on Vehicle Propulsion Subsystem

2019-09-09
2019-24-0079
An increasing demand for reducing cost and time effort of the design process via improved CAE (Computer-Aided Engineer) tools and methods has characterized the automotive industry over the past two decades. One of the main challenge regarded the effective simulation of a vehicle’s propulsion system dealing with different physical domains: several examples have been proposed in literature mainly based on co-simulation approach which involves a specific tool for each propulsion system part modeling. Nevertheless, these solutions are not fully suitable and effective to perform statistical analysis including all physical parameters. In this respect, this paper presents the definition and implementation of a new simulation methodology applied to a propulsion subsystem.
Technical Paper

Knock Mitigation by Means of Coolant Control

2019-09-09
2019-24-0183
The potentiality of knock mitigation by means of the control of the coolant flow rate is investigated. As a first step, the dynamic behavior of the wall temperature in response to a sudden variation of the coolant flow rate is analyzed experimentally in a small displacement, 4-valve per cylinder SI engine, which is equipped with an electrically driven pump. Subsequently, the influence of the wall temperature on knock onset is analyzed through a zero-dimensional model and the Livengood and Wu integral. Finally, an experimental activity on the engine test bed is carried-out in order to evaluate the influence of the coolant flow rate and of the engine inlet coolant temperature on the knock phenomenon. Results show that, even though a retarded spark advance and a mixture enrichment are not avoidable in the early stage of knock onset, a cooling control can help reducing the time of use of these fuel consuming strategies in the case of prolonged high-load conditions.
Technical Paper

Experimental Investigation on the Use of Argon to Improve FMEP Determination Through Motoring Method

2019-09-09
2019-24-0141
Mechanical friction is still one of the current topics in internal combustion engine research and development. In the ever increasing challenge of developing more efficient and less polluting engines, friction reduction is of significant importance; whose investigation needs an accurate and reliable measurement technique. The Pressurized Motoring method is one of the techniques used for both friction and heat transfer measurements in internal combustion engines. This method is able to simulate mechanical loading on the engine components similar to the fired conditions. It also allows measurement of friction mean effective pressure (FMEP) with a much smaller uncertainty as opposed to that achieved from a typical firing setup. Despite its advantages, this method of FMEP determination is usually criticized over the fact that the thermal conditions imposed in pressurized motoring are far detached from those seen in fired conditions, hence not able to simulate the complete effects on FMEP.
Technical Paper

Study of Friction Optimization Potential for Lubrication Circuits of Light-duty Diesel Engines

2019-09-09
2019-24-0056
Over the last two decades, engine research has been mainly focused on reducing fuel consumption in view of compliance with stringent homologation targets and customer expectations. As it is well known, the objective of overall engine efficiency optimization can be achieved only through the improvement of each element of the efficiency chain, of which mechanical constitutes one of the two key pillars (together with thermodynamics). In this framework, the friction reduction for each mechanical subsystems has been one of the most important topics of modern diesel engine development. In particular, the present paper analyzes the lubrication circuit potential as contributor to the mechanical efficiency improvement, by investigating the synergistic impact of oil circuit design, oil viscosity characteristics (including new ultra-low formulations) and thermal management. For this purpose, a combination of theoretical and experimental tools were used.
Technical Paper

Oxy-Fuel HCCI Combustion in a CFR Engine with Carbon Dioxide as a Thermal Buffer

2019-09-09
2019-24-0119
A basic formula inspired by the Otto engine cycle shows that the thermodynamic efficiency of the engine increases as the mixture specific heat ratio and compression ratio increase. Homogenous charge compression ignition (HCCI) engines allow the combustion of a lean mixture at relatively higher compression ratios increasing the thermodynamic efficiency. At the same time, it is also a low temperature combustion and this means lower NOx emissions. One way to increase the thermodynamic efficiency of the engine is to increase the specific heat ratio by replacing the nitrogen in the oxidizer by a monoatomic gas that has the highest possible specific heat ratio. However, higher specific heat ratio results in elevated cylinder temperature and pressure leading to engine knock. The compression ratio is thus decreased to avoid this phenomenon. Also, elevated engine temperature will oxidize any nitrogen (no matter how small) forming undesired NOx emissions.
Technical Paper

Temperature Measurements of the Piston surface in a Research Compression Ignition Engine in Transient Conditions for 1d Model of Heat Transfer

2019-09-09
2019-24-0182
Analysis of heat losses in internal combustion engines (ICEs) is fundamental to evaluate and improve the engine efficiency. Detailed and reliable heat transfer models are required for more complex 1d-3d combustion models. At the same time, the thermal status of engine components, as pistons, is needed for an efficient design. Measurements of piston temperature during ICEs operation represent a precious and challenging result to get for the aforementioned purposes. In previous works, the authors, first, evaluated and, then, measured the temperature of the optical window in a research compression ignition engine via thermal imaging and thermocouple installation, respectively. The tests concerned steady state and transient conditions.
Technical Paper

Efficient Test Bench Operation with Early Damage Detection Systems

2019-09-09
2019-24-0192
The efficient operation of test benches within the framework of research and development projects directly correlates with the "health" of the examinee to be investigated. The use of so-called Early Damage Detection Systems (EDDS) is becoming increasingly popular for reasons of Unit Under Test (UUT) monitoring. In the context of this publication the expectations of an EDDS and its structure are discussed as well as its advantages and disadvantages in test bench operation analyzed and compared with the results of measurements. The used EDDS should primarily prevent the damage, up to the loss of the test object by a total loss, in order to ensure a finding possibility of the damaged part at the examined test object. A deviation of the test object behavior from the undamaged condition must be recognized in an early status and must lead to a shutdown of the test bench operation after reaching a defined limit value.
Technical Paper

A Coupled Lattice Boltzmann-Finite Volume Method for the Thermal Transient Modeling of an Air-Cooled Li-ion Battery Module for Electric Vehicles

2019-09-09
2019-24-0207
Due to their ability to store higher electrical energy, lithium ion batteries are the most promising candidates for electric and hybrid electric vehicles, whose market share is growing fast. Heat generation during charge and discharge processes, frequently undergone by these batteries, causes temperature increase and thermal management is indispensable to keep temperature in an appropriate level. In this paper, a coupled Lattice Boltzmann-Finite Volume model for the three-dimensional transient thermal analysis of an air-cooled Li-ion battery module is presented. As it has already been successfully used to deal with several fluid dynamics problems, the Lattice Boltzmann method is selected for its simpler boundary condition implementation and complete parallel computing, which make this approach promising for such applications.
Technical Paper

Heat Transfer Characterization of Catalytic Converter Substrates During Warm-Up

2019-09-09
2019-24-0163
The transient heat transfer behavior of a real size automotive catalytic reactor has been simulated with OpenFOAM in 1D. The model takes into consideration the gas-solid convective heat transfer, axial wall conduction and heat capacity effects in the solid phase, but also the chemical reactions of CO and C3H6 oxidations, based on simplified Arrhenius and Langmuir-Hinshelwood approaches. The associated parameters have been chosen based on the tuning of experimental data. The impact of different initial catalytic converter temperatures, inlet flow temperatures and inlet flow rates have been quantified, even in terms of overall cumulative emissions. . A dimensional analysis is proposed and dimensionless temperature difference and space-time coordinate are defined. Using this suitably modified coordinates, for the case of negligible axial solid conduction, computed solid temperature at the reactor outlet lay on the typical S-curve.
Technical Paper

Development and Validation of SI Combustion Models for Natural-Gas Heavy-Duty Engines

2019-09-09
2019-24-0096
Flexible, reliable and consistent combustion models are necessary for the improvement of the next generation spark-ignition engines. Different approaches have been proposed and widely applied in the past. However, the complexity of the process involving ignition, laminar flame propagation and transition to turbulent combustion need further investigations. Purpose of this paper is to compare two different approaches describing turbulent flame propagation. The first approach is the one-equation flame wrinkling model by Weller, while the second is the Coherent Flamelet Model (CFM). Ignition is described by a simplified deposition model while the correlation from Herweg and Maly is used for the transition from the laminar to turbulent flame propagation. Validation of the proposed models was performed with experimental data of a natural-gas, heavy duty engine running at different operating conditions.
Technical Paper

CFD Modeling of Compact Heat Exchangers for I.C. Engine Oil Cooling

2019-09-09
2019-24-0179
In the last years, the increase of the specific power of the modern engines has required a parallel improvement of the performances of the cooling system. In this context, also the control of the oil temperature has become an important issue, leading to the introduction of dedicated cooling circuits (air-cooled or liquid-cooled). Among the two, the liquid-cooled solution results in a more compact installation in which the oil-to-liquid heat exchanger is directly mounted on the engine block and integrated in the engine cooling system. It is clear that, in a liquid-cooled solution, the design of the heat exchanger represents an issue of extreme concern, which requires a compromise between different objectives: high compactness, low pressure drop, high heat-transfer efficiency. In this work, a computational framework for the CFD simulation of compact oil-to-liquid heat exchangers, including offset-strip fins as heat transfer enhancer (turbolator), has been developed.
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