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A Detailed Finite Element Thermal Analysis of a 18650 Format Battery Cell for Automotive Applications

University of Modena and Reggio Emilia-Saverio Giulio Barbieri, Valerio Mangeruga, Dario Cusati, Matteo Giacopini, Francesco Cicci
  • Technical Paper
  • 2020-37-0022
To be published on 2020-06-23 by SAE International in United States
This paper presents a methodology for the thermal analysis of a cylindrical Li-Ion battery cell. In particular, the 18650 format is considered. First, an electrical current drain cycle is applied to measure the electrical internal resistance of the cell and to estimate the consequent thermal energy release. A battery cell is then dissected and the inner structure is reproduced in detail with the adoption of microscopic images. By this way, the heat generation areas and the different thermal paths are correctly identified. Thermal Finite Element analyses are performed faithfully reproducing the inner geometry of the cell, and different cooling strategies are compared. The numerical results are then validated versus experimental evidence obtained considering the thermal behaviour of a small section, made by three cells, of a water cooled battery pack. The proposed approach can drive the design process towards more efficient battery pack cooling strategies. The numerical model may be then applied to perform thermo-structural analyses and, consequently, structural failures of the battery cells might be predicted.
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Numerical Analysis of the Influences of Wear on the Vibrations of Power Units

Goethe-Universität-Lars Hedrich
Robert Bosch GmbH-Yashwant Kolluru, Rolando Doelling
  • Technical Paper
  • 2020-01-1506
To be published on 2020-06-03 by SAE International in United States
Numerical Analysis of the Influences of Wear on the Vibrations of Power Units Yashwant Kolluru, Rolando Doelling eBike Department Robert Bosch GmbH Kusterdingen, Germany yashwant.kolluru@de.bosch.com rolando.doelling@de.bosch.com Lars Hedrich Institute of Informatics Goethe University Frankfurt Frankfurt, Germany hedrich@em.informatik.uni-frankfurt.de The prime factor, which influences vibrations of electro-mechanical drives, is wear at the components. This paper discusses the numerical methods developed for abrasion, vibration calculations and the coupling between wear and NVH models of drive unit. Wear is a complex process and understanding it is essential for vibro-acoustics. The paper initially depicts finite element static model used for wear calculations. The special subroutines developed, aids in coupling the wear equations, various contact and friction formulations to the numerical model. The vibration domain model initially, focuses on calculations of mechanical excitation's at the gear shafts, which are generated via a nonlinear dynamic model. Furthermore, the bearings are studied for the influences on its stiffness and eventually its impact on harmonics of the drive trains. Later, free and forced vibrations of the complete drive train are simulated via steady-state dynamic…
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Micro-Macro Acoustic Modeling of Heterogeneous Foams with Nucleation Perturbation

Duke University-Johann Guilleminot
Ecole des Ponts ParisTech-Michel BORNERT
  • Technical Paper
  • 2020-01-1526
To be published on 2020-06-03 by SAE International in United States
The properties of a polyurethane foam are greatly influenced by the addition of graphite particles during the manufacturing process, initially used as a fire retardant. These thin solid particles perturbate the nucleation process by generating bubbles in its immediate vicinity. The preponderance of work so far has focused on foams that are locally relatively homogeneous. We propose a model for locally inhomogeneous foams (including membrane effects) consisting of a random stack of spheres that permits one to represent certain pore size distribution functions. The cellular structure of the foam is obtained through a Laguerre tessellation and the solid skeleton determined from the minimization of surface energy (Surface Evolver). The structure of real foam samples is analyzed using X-ray computed tomography and scanning electron microscopy followed by image processing to create computerized three-dimensional models of the samples. The corresponding effective material parameters, including the permeability, the tortuosity and the viscous characteristic length are computed by applying a numerical homogenization approach. All the numerical data are presented, discussed and further compared with experimental results.
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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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Improved Wear Resistance of Austempered Gray Cast Iron Using Shot-Peening Treatment

Oakland University-Yu Liu, Gary Barber
Zhejiang Sci-Tech University-Weiwei Cui, Bingxu Wang
  • Technical Paper
  • 2020-01-1098
To be published on 2020-04-14 by SAE International in United States
In this research, ball-on-plate reciprocating sliding wear tests were utilized on austempered and quench-tempered gray cast iron samples with and without shot-peening treatment. The wear volume loss of the gray cast iron samples with different heat treatment designs was compared under equivalent hardness. The phase transformation in the matrix was studied using metallurgical evaluation and hardness measurement. It was found that thin needle-like ferrite became coarse gradually with increasing austempering temperature and was converted into feather-like shape when using the austempering temperatures of 399°C (750°F). The residual stress on the surface and sub-surface before and after shot-peening treatment was analyzed using x-ray diffraction. Compressive residual stress was produced after shot-peening treatment and showed an increasing trend with austempering temperature. In sliding wear tests, austempered gray cast iron had lower wear volume loss than quench-tempered gray cast iron before and after shot-peening treatment. The wear tracks were examined using scanning electron microscopy. Delamination and smearing were the main wear mechanisms on the gray cast iron samples.
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Waste Egg shell as heterogeneous nanocatalyst for biodiesel production: Optimization and Engine Characteristics study.

CK College of Engineering & Technology-R Krishnamoorthy
Mepco Schlenk Engineering College-Dhinesh Balasubramanian, Sriram Kamaraj
  • Technical Paper
  • 2020-01-0341
To be published on 2020-04-14 by SAE International in United States
The objective of our present work is preparation of low cost heterogeneous calcium oxide catalyst from egg shell for the waste cooking oil biodiesel production and optimization. The egg shell catalyst was prepared by calcination at the temperature range of 300-900 and characterized using scanning electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX) and Fourier Transform Infrared Spectroscopy (FTIR). The transesterification process was catalyzed by calcinated egg shell catalyst and the biodiesel yield% was optimized by varying parameters such as reaction temperature and time, catalyst weight and methanol to oil molar ratio. The L9 orthogonal array was selected for the Taguchi optimization. Among the selected parameter's temperature and methanol to oil ratio were found to be maximum influencing parameters. The maximum biodiesel yield% was 94.3% and this was obtained at temperature of 60 ºC, 6wt% catalyst weight%, and 4 hrs. time and 12:1 methanol to oil ratio levels. The egg shell catalyst calcinated at 900ºC has shown good regeneration capacity. The biodiesel %yield was 76% even after the five transesterification cycles. This is an additional advantage…
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Recent Progress on In-Situ Monitoring and Mechanism Study of Battery Thermal Runaway Process

Soundon New Energy Technology Co.-Haonan Zhang
Tongji University-Tang Xuan, Xueyuan Wang, Haifeng Dai, Jun Sun, Guangxu Zhang
  • Technical Paper
  • 2020-01-0861
To be published on 2020-04-14 by SAE International in United States
Lithium-ion batteries (LIBs) with relatively high energy, power density and eco-friendly characteristic are considered as a vital energy source in consumer market of portable electronics and transportation sector especially in electric vehicles (EVs). To meet the higher capacity requirements, the nickel-rich LIBs with higher capacity has been used as the commercial power batteries. However, the battery with higher energy density is more destructive, which could result in thermal runaway accidents and make the battery safety issues become more and more prominent. Thermal runaway of LIBs is one of the key scientific problems in safety issues. Until now, the inducement of thermal runaway process is complicated which perplex researchers and industry a lot. On the one hand, the internal mechanism about thermal runaway should be deeply studied. On the other hand, in-situ monitoring should be developed to supply the mechanism study and early warning. In this paper, the latest evolution about LIBs thermal runaway is highlighted. The internal mechanism of chain reactions during thermal runaway process is summarized. Furthermore, different in-situ monitoring technologies to investigate the…
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Impact of the Injection Strategy on Soot Reactivity and Particle Properties of a GDI Engine

Amin Velji, Henning Bockhorn, Dimosthenis Trimis
Diploma Engineer-Sergej Koch
  • Technical Paper
  • 2020-01-0392
To be published on 2020-04-14 by SAE International in United States
The gradual global tightening of emission legislation for particulate matter emissions requires the development of new gasoline engine exhaust aftertreatment systems. For this reason, the development of gasoline direct injection engines aims at the reduction of particulate emissions by application of a Gasoline Particulate Filter (GPF). The regeneration temperature of GPF depend on soot reactivity towards oxidation and therefore on particle properties. In this study, the soot reactivity is correlated with nanostructural characteristics of primary gasoline particles as a function of specific engine injection parameters. The investigations on particle emissions were carried out on a turbocharged 4-cylinder GDI-engine that allows the variation of injection parameters. The emitted engine soot particles have been in-situ characterized towards their number and size distribution using an engine exhaust particle sizer (EEPS). Ex-situ analytics focuses on the analysis of oxidation kinetics and the nanostructural characteristics affecting soot reactivity significantly. The oxidation kinetics were determined by temperature programmed oxidation (TPO) employing thermogravimetric analysis (TGA). The temperature at the maximum of the reaction rate is referred to Tmax, where low temperatures are…
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The Influence of the Operating Duty Cycles on the Composition of Exhaust Gas Recirculation Cooler Deposits of Industrial Diesel Engines

Industrial Power Alliance, Ltd.-Minato Tomuro
University of Michigan-Jason Hebert, John Hoard, André Boehman
  • Technical Paper
  • 2020-01-1164
To be published on 2020-04-14 by SAE International in United States
Exhaust Gas Recirculation (EGR) coolers are commonly used in on-road and off-road diesel engines to reduce the recirculated gas temperature in order to reduce NOx emissions. One of the common performance behaviors for EGR coolers in use on diesel engines is a reduction of the heat exchanger effectiveness, mainly due to particulate matter (PM) deposition and condensation of hydrocarbons (HC) from the diesel exhaust on the inside walls of the EGR cooler. According to previous studies, typically, the effectiveness decreases rapidly initially, then asymptotically stabilizes over time. Prior work has postulated a deposit removal mechanism to explain this stabilization phenomenon. In the present study, five field aged EGR cooler samples that were used on construction machines for over 10,000 hours were analyzed in order to understand the deposit structure as well as the deposit composition after long duration use. Three of them were disassembled from 15.2L off-road diesel engines, the rest of two were taken from 23.1L off-road diesel engines, then torn down to analyze the deposits. The duty cycle of each vehicle was calculated…
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Investigation of Mechanical Behavior of Chopped Carbon Fiber Reinforced Sheet Molding Compound (SMC) Composites

Ford Motor Company-Carlos Engler-Pinto, Li Huang, Xuming Su
Ford Motor Research & Eng. (Nanjing) Co.-Shiyao Huang
  • Technical Paper
  • 2020-01-1307
To be published on 2020-04-14 by SAE International in United States
As an alternative lightweight material, chopped carbon fiber reinforced Sheet Molding Compound (SMC) composites, formed by compression molding, provide a new material for automotive applications. In the present study, the monotonic and fatigue behavior of chopped carbon fiber reinforced SMC is investigated. Tensile tests were conducted on coupons with three different gauge length, and size effect was observed on the fracture strength. Since the fiber bundle is randomly distributed in the SMC plaques, a digital image correlation (DIC) system was used to obtain the local modulus distribution along the gauge section for each coupon. It was found that there is a relationship between the local modulus distribution and the final fracture location under tensile loading. The fatigue behavior under tension-tension (R=0.1) and tension-compression (R=-1) has also been evaluated. Damage evolution on the free edge of the samples under cyclic loading has been recorded using optical microscopy by interrupting fatigue tests at different number of cycles. The results suggest that the interfacial failure between fiber and matrix is the dominant damage mechanism for SMC under fatigue…