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Effect of Geometry Variation in a Polymer Electrolyte Membrane Fuel Cell

Siemens Digital Industries Software-Carlo Locci, Chris Lueth, Huong Nguyen, Karin Frojd
  • Technical Paper
  • 2020-01-1174
To be published on 2020-04-14 by SAE International in United States
Water transport at high current densities is of main concern for polymer electrolyte membrane (PEM) fuel cells. The water content of the membrane must be high enough to provide maximum electrical conductivity and thus optimal stack performance. Dry-out may also lead to membrane degradation. However, a too high level of humidity leads to cell flooding, blocking the air and fuel flows to the catalyst sites and thus the reactions, resulting in a drop-in efficiency. Fuel cells water transport physics requires further investigation due to its complexity [1,2] and numerical modelling can improve the fundamental understanding of the phenomena. In this work, a 3D comprehensive model for fuel cells is presented. The PEM fuel cell is modelled in Siemens Simcenter STAR-CCM+ [3]. Anode and cathode GDL are modelled as porous media, with electrochemical reactions calculated in an infinitely thin catalyst layer. The membrane is modelled as a solid block including proton and water transport with electro-osmotic drag as well as ohmic heating. A two-phase approach is used to model the gas mixture and liquid water transport…
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LOW COST ELECTROMAGNETIC SHIELDING MATERIAL BASED ON POLYPYRROLE-BIO WASTE COMPOSITES

Dongguk University-Ganapathi Nagarajan
Hindustan University-Sheeba Rathina Selvi, Srimathi Krishnaswamy, Puspamitra Panigrahi
  • Technical Paper
  • 2020-01-0226
To be published on 2020-04-14 by SAE International in United States
There is a crucial need of Electromagnetic interference shielding in many of the applications in this digital world with low cost and high efficient shielding materials. Electrically conducting heterocyclic polymer polypyrrole has found its application as an EMI shielding materials due to its conducting property. Electrically conducting polypyrrole (PPy) coated on coconut fibres (coir) with different morphology, were prepared through in-situ chemical polymerization of PPy using strong oxidizing agent like ammonium per sulfate. The synthesized PPy on coconut fibre were characterised using UV-Visible spectrophotometer(UV-VIS) and Fourier transform infrared spectroscopy (FTIR) which confirmed the product formation. The morphology was done using Scanning electron Microscopy(SEM).Thermal studies were performed by Thermo Gravimetric analysis (TGA). The effect of PPy morphology and content in composite with coir on the DC conductivity and shielding effectiveness (SE) were investigated. The shielding effectiveness was calculated theoretically and well matched with the experimental values.
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Development of Cooling Fan Model and Heat Exchange Model of Condenser to Predict the Cooling and the Heat Resistance Performance of Vehicle

Honda R&D Co., Ltd.-Yuichi Fukuchi, Kunihiko Yoshitake, Kazutaka Yokota
  • Technical Paper
  • 2020-01-0157
To be published on 2020-04-14 by SAE International in United States
The cooling performance and the heat resistance performance of commercial vehicle are balanced with aerodynamic performance, output power of powertrain, styling, cost and many other parameters. Therefore, it is desired to predict the cooling performance and the heat resistance performance with high accuracy at the early stage of development. Among the three basic forms of heat transfer (conduction, convection and radiation), solving thermal conduction accurately is difficult, because modeling of “correct shape” and setting of coefficient of thermal conductivity for each material need many of time and efforts at the early stage of development. Correct shape means that each part should be attached correctly to generate the solid mesh with high quality. Therefore, it is more efficient and realistic method to predict the air temperature distribution around the rubber/resin part instead of using the surface temperature at the preliminary design stage. The air temperature distribution in the engine compartment is dominated by the flow distribution from fans, the heat rejected by heat exchangers, AC-generator and the convecting heat by surface temperature of parts. In the…
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Simulation and Parametric Analysis of Battery Thermal Management System Using Phase Change Material

CATARC-Chunjing Lin, Yuhan Sun
Tongji University-Zhao Li, Sichuan Xu
  • Technical Paper
  • 2020-01-0866
To be published on 2020-04-14 by SAE International in United States
The thermophysical parameters and amount of composite phase change materials (PCMs) have decisive influence on the thermal control effects of thermal management systems (TMSs). At the same time, the various thermophysical parameters of the composite PCM are interrelated. For example, increasing the thermal conductivity is bound to mean a decrease in the latent heat of phase change, so a balance needs to be achieved between these parameters. In this paper, a prismatic LiFePO4 battery cell cooled by composite PCM is comprehensively analyzed by changing the phase change temperature, thermal conductivity and amount of composite PCM. The influence of the composite PCM parameters on the cooling and temperature homogenization effect of the TMS is analyzed. which can give useful guide to the preparation of composite PCMs and design of the heat transfer enhancement methods for TMSs.
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An Electric Motor Thermal Bus Cooling System for Vehicle Propulsion - Design and Test

CCDC Ground Vehicle Systems Center-Katherine Sebeck
Clemson University-Shervin Shoai Naini, Richard Miller, John Wagner
  • Technical Paper
  • 2020-01-0745
To be published on 2020-04-14 by SAE International in United States
Automotive and truck manufacturers are introducing electric propulsion systems into their ground vehicles to reduce fossil fuel consumption and harmful tailpipe emissions. The mobility shift to electric motors requires a compact thermal management system that can accommodate heat dissipation demands with minimum energy consumption in a confined space. An innovative cooling system design, emphasizing passive cooling methods coupled with a small liquid system, using a thermal bus architecture has been explored. The laboratory experiment features an emulated electric motor interfaced to a thermal cradle and multiple heat rejection pathways to evaluate the transfer of generated heat to the ambient surroundings. The thermal response of passive (e.g., carbon fiber, high thermal conductivity material, thermosyphon) and active cooling systems are investigated for two operating scenarios. The test results demonstrate that up to 93% improvement can be achieved in cooling system energy consumption during a light load electric motor condition while maintaining a target core temperature of 70°C. The governing thermal system dynamics will be reviewed in discussion of the experimental observations.
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Thermal performance augmentation of automobile radiator using water-based Al2O3 and CuO nanofluid as a coolant

S V National Inst. of TechnologySurat-Akashkumar Pravinbhai Parmar
S.V. National Inst. of Technology, Surat-Mahendrakumar Maisuria, Manishkumar K. Rathod
  • Technical Paper
  • 2020-01-1340
To be published on 2020-04-14 by SAE International in United States
In the recent past, rapid development in the performance of vehicle engine has taken place. Attempts are going on to produce high-efficiency engines at a minimum possible cost in order to fulfill the requirements of customers. However, usage of low thermal conductivity engine coolant limits the ability of cooling system to extract the heat, which ultimately results into difficulties in maintaining the compact size of cooling system. Also, increasing the cooling rate by conventional technologies i.e. providing fins and microchannel has already reached their limits. One of the alternative efforts to improve cooling rate in an automotive radiator to immerge and analyze new types of cooling fluids. Thus, in the present work, the experimental and analytical analysis is carried out to investigate the thermal performance of corrugated finned flat tube car radiator using water-based Al2O3 and CuO Nano fluid. Augmentation of heat transfer process is studied for Nano fluid in comparison to water coolant. The Nano fluid is prepared considering 0.2% Vol. concentration of Nanoparticle with water as a base fluid. A numerical code is…
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Comprehensive 3D Thermal Modeling of Vehicle-Ready Battery Module

SERES-Aditya Velivelli, Saeed Khaleghi Rahimian, Yifan Tang
  • Technical Paper
  • 2020-01-1385
To be published on 2020-04-14 by SAE International in United States
Thermal management of vehicle battery pack is crucial in determining the life/ageing of the battery pack, in establishing the range of the vehicle on a day to day basis and in determining the safety of the vehicle and occupants. An effective design of a thermal management system cannot be established solely through experimentation as it is time consuming and costly. Accurate computational models are required to aid in the design process. This study describes the development and validation of 3D computational model for simulating electrical and thermal characteristics of a vehicle-ready battery module. The modeling process starts with the full 3D CAD geometry of the module including the coolant channels and cold plate. As part of the study, an experimental test case was setup. This included a climate chamber for the initial soak of the module and to control ambient temperature. Coolant was pumped through channels underneath the cold plate atop which the cells sat in blocks. The cell bottom area conducted heat through a thermal interface material and through the cold plate. The effectiveness…
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Microstructure-Fatigue Property Relationships for Cast Irons

National Research Council (Canada)-Xijia Wu
  • Technical Paper
  • 2020-01-0187
To be published on 2020-04-14 by SAE International in United States
Cast irons are widely used for combustion engine/exhaust system applications, not only because they are less expensive but also because they offer some attractive properties such as good thermal conductivity, relatively high specific yield strength, and good oxidation resistance. Cast irons can be made with a wide variety of microstructures containing either flake-like graphite (FG), nodular graphite (NG) or vermicular graphite (VG), or mixing of the above, which control their mechanical and fatigue properties. In this paper, a microstructure-fatigue property relationship model is developed, combining the Tanaka-Mura-Wu’s fatigue crack nucleation model with Eshelby’s solution for materials containing ellipsoidal inclusions. This applies to cast irons considering its microstructural graphite characters (shape, size, elastic modulus and Poisson’s ratio). This model is used to analyse ductile cast iron (DCI) with nodular graphite (NG) microstructure, grey cast iron (GCI) with flake-like graphite (FG) microstructure, and compacted graphite iron (CGI) with vermicular graphite (VG) microstructure. Excellent agreement is found between the model prediction and the experimental data or the Coffin-Manson-Basquin correlations at room temperature. Further development will be to incorporate…
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Experimental Investigation of Low Cost, Low Thermal Conductivity Thermal Barrier Coating on HCCI Combustion, Efficiency, and Emissions

Auburn University-Mark Hoffman
Bosch Packaging Technology Inc.-Ryan O'Donnell
  • Technical Paper
  • 2020-01-1140
To be published on 2020-04-14 by SAE International in United States
In-cylinder surface temperature is of heightened importance for Homogeneous Charge Compression Ignition (HCCI) combustion, as the combustion mechanism is thermo-kinetically driven. Thermal Barrier Coatings (TBCs) selectively manipulate the in-cylinder surface temperature, providing an avenue for improving thermal and combustion efficiency. This thermal phenomenon sidesteps charge preheating during gas exchange, while a surface temperature swing during combustion/expansion reduces heat transfer losses, leading to more complete combustion and reduced emissions. The magnitude and profile of the dynamic surface temperature swing was found to be affected by the material properties and TBC thickness. This study is the continuation of the author’s work to systematically engineer coatings that are best suited for HCCI. A parametric study was used to assess the impacts of various TBC material properties (density, specific heat, thermal conductivity) on the temperature swing effect. Previous work investigated the effect of reducing TBC density via increased porosity, however fuel entrapment and durability concerns found this route initially unattractive for robust TBC performance. Shifting focus to the remaining material properties, this study experimentally investigates the impact of lower…
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Transient Simulation of Heat Exchangers with Phase Change Material

MAHLE (retired)-Timothy Craig
MAHLE Behr USA, Inc.-Yanping Xia, Edward Wolfe
  • Technical Paper
  • 2020-01-0156
To be published on 2020-04-14 by SAE International in United States
Heat exchangers with Phase Change Material (PCM) are finding more energy storage applications for both Internal Combustion Engine Vehicles (ICEVs) and Electric Vehicles (EVs). These applications include cold storage evaporators for stop-start cars, thermal storage system for EV cabin heating and cooling, and other Heating, Ventilation, and Air Conditioning (HVAC) and Power Train Cooling (PTC) peak load shaving applications.The energy stored in a PCM heat exchanger is typically charged/discharged using refrigerant, coolant, or air, depending on the system design of different applications. Due to the low thermal conductivity of state-of-art PCM, the PCM heat exchangers generally rely on aluminum fins to enhance the speed of charging and discharging of the stored energy. Different fin shape, height and density will result in different PCM freezing/melting rate.In this paper, two different fin designs (folded-sine-wave fin and off-set-strip fin) are simulated with Computational Fluid Dynamics (CFD) to compare the melting time of a hot PCM with respect to different operating parameters (coolant temperature, coolant convection heat transfer coefficient, and PCM initial temperature). Next, a 1-Dimensional (1-D) approximation of…