The aim of this project is to design and develop an electrically operated automatic mobility device for personal transportation in short range mobility. According to design and functional requirements, different mechanical and electrical components have been selected for the implementation. In today’s world this personal mobility product allow us to travel convenient, quick, safe and without any harm to environment. This report includes design, analysis and manufacturing strategy for the electric mobility device. This device is specially designed for short range transportation. It is cost effective, efficient and environment friendly device.
{"title":"Design and Development of a Short Range Electric Mobility Device","authors":"Ishan Hiremath, Avanti Nalawade","doi":"10.37285/ajmt.2.3.9","DOIUrl":"https://doi.org/10.37285/ajmt.2.3.9","url":null,"abstract":"The aim of this project is to design and develop an electrically operated automatic mobility device for personal transportation in short range mobility. According to design and functional requirements, different mechanical and electrical components have been selected for the implementation. In today’s world this personal mobility product allow us to travel convenient, quick, safe and without any harm to environment. This report includes design, analysis and manufacturing strategy for the electric mobility device. This device is specially designed for short range transportation. It is cost effective, efficient and environment friendly device.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134497749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanjay D. Patil, Vikas T. Mujmule, Ajay P. Mahale, Suhas A. Jagtap, Ganesh S. Patil
Aerodynamic drag force is one of the main obstacles on moving a vehicle. This force significantly reduces a vehicle's speed and, as a result, its fuel efficiency. In today’s scenario, fuel efficiency is a prime concern in vehicle design, so a reduction in aerodynamic drag force is highly important. Road vehicles are designed to pass through surrounding air and displace it as efficiently as possible. Due to the rear shape of a car, airflow suddenly separates from the vehicle at a point near the rear windscreen. This flow separation at the rear end of the car is responsible for the drag force, which is the main opposition to the vehicle's forward motion. This drag force is proportional to the square of the velocity of the car and, as a result, increases significantly after certain speeds. To reduce the drag force, the flow separation at the rear end needs to be avoided. In hatch-back type cars, to avoid this separation, a vortex generator (VG) can be used. VG creates the vortex at the rear end of the car, which delays the flow separation and, ultimately, drag is reduced significantly. In this work, the effect of a VG on the pressure distribution, velocity destitution and aerodynamic drag on the hatchback type car, is studied by the numerical simulation. The numerical simulations are carried out using the ANSYS FLUENT® software. The simulation setup is validated with wind tunnel test results.
{"title":"Effects of Vortex Generators on Aerodynamic Drag Force in the Hatchback Type Car","authors":"Sanjay D. Patil, Vikas T. Mujmule, Ajay P. Mahale, Suhas A. Jagtap, Ganesh S. Patil","doi":"10.37285/ajmt.1.2.3","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.3","url":null,"abstract":"Aerodynamic drag force is one of the main obstacles on moving a vehicle. This force significantly reduces a vehicle's speed and, as a result, its fuel efficiency. In today’s scenario, fuel efficiency is a prime concern in vehicle design, so a reduction in aerodynamic drag force is highly important. Road vehicles are designed to pass through surrounding air and displace it as efficiently as possible. Due to the rear shape of a car, airflow suddenly separates from the vehicle at a point near the rear windscreen. This flow separation at the rear end of the car is responsible for the drag force, which is the main opposition to the vehicle's forward motion. This drag force is proportional to the square of the velocity of the car and, as a result, increases significantly after certain speeds. To reduce the drag force, the flow separation at the rear end needs to be avoided. In hatch-back type cars, to avoid this separation, a vortex generator (VG) can be used. VG creates the vortex at the rear end of the car, which delays the flow separation and, ultimately, drag is reduced significantly. In this work, the effect of a VG on the pressure distribution, velocity destitution and aerodynamic drag on the hatchback type car, is studied by the numerical simulation. The numerical simulations are carried out using the ANSYS FLUENT® software. The simulation setup is validated with wind tunnel test results.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116163736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Structural response of battery packs in electric vehicles when subjected to road loads is an important factor that decides its performance and life during normal operation. In this paper a kriging response surface model is built using a Design of Experiment (DOE) run dataset to predict structural response and global modal frequency metrics of the battery pack. Using this Response Surface Model (RSM), we can rapidly optimize the battery pack design with respect to structural response and achieve significant mass reduction. This method reduces turnaround times for design optimization in early stages of battery pack design.
{"title":"On Using Kriging Response Surface Method for EV Battery Pack Structural Response Prediction and Mass Optimization","authors":"Deepak Sreedhar Kanakandath, Sankha Subhra Jana, Arunkumar Ramakrishnan","doi":"10.37285/ajmt.1.2.8","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.8","url":null,"abstract":"Structural response of battery packs in electric vehicles when subjected to road loads is an important factor that decides its performance and life during normal operation. In this paper a kriging response surface model is built using a Design of Experiment (DOE) run dataset to predict structural response and global modal frequency metrics of the battery pack. Using this Response Surface Model (RSM), we can rapidly optimize the battery pack design with respect to structural response and achieve significant mass reduction. This method reduces turnaround times for design optimization in early stages of battery pack design.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123676045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Major Systems of an internal combustion Engine are Air System, Fuel system, and Exhaust system. Any malfunction in these systems increases emissions. OBD legislation mandates to monitor these systems for any faults and appropriate action should be taken in case of the any faults which increase vehicle emissions. The idea of the paper is to find the Air mass flow deviation faults using datamining and machine learning based approach. Detection of fault is classifying whether system is faulty or not. Objective is to create a deep learning model using the available vehicle data to classify the system for a fault. Three main inputs for the Air Mass flow in an internal combustion Engine are1) Fresh Air which measure using Mass Air Flow sensor2) Low Pressure EGR3) High Pressure EGRDuring vehicle lifetime, due to different real vehicle operating conditions and environmental conditions, deviation in the set point of air mass flow and actual mass flow are possible to an extent, which can affect vehicle emissions. Deviation in the Air Mass flow can be caused by intake Air mass, LP-EGR, HP-EGR. The Aim of the project is to create the deep learning model for Air Mass Flow Hi and Low faults using the available data, and associate the fault to the component in the Intake Air System.
{"title":"Deep Learning Model for Prediction of Air Mass Deviation Faults","authors":"Karthik Chinnapolamada","doi":"10.37285/ajmt.1.2.4","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.4","url":null,"abstract":"Major Systems of an internal combustion Engine are Air System, Fuel system, and Exhaust system. Any malfunction in these systems increases emissions. OBD legislation mandates to monitor these systems for any faults and appropriate action should be taken in case of the any faults which increase vehicle emissions. The idea of the paper is to find the Air mass flow deviation faults using datamining and machine learning based approach. Detection of fault is classifying whether system is faulty or not. Objective is to create a deep learning model using the available vehicle data to classify the system for a fault. Three main inputs for the Air Mass flow in an internal combustion Engine are1) Fresh Air which measure using Mass Air Flow sensor2) Low Pressure EGR3) High Pressure EGRDuring vehicle lifetime, due to different real vehicle operating conditions and environmental conditions, deviation in the set point of air mass flow and actual mass flow are possible to an extent, which can affect vehicle emissions. Deviation in the Air Mass flow can be caused by intake Air mass, LP-EGR, HP-EGR. The Aim of the project is to create the deep learning model for Air Mass Flow Hi and Low faults using the available data, and associate the fault to the component in the Intake Air System.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132247594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the competitive automotive industry, launch of a new vehicle has become a norm to stay ahead, also the vehicle manufacturers are competing in terms of increased warranty on the new launch. Hence it is imperative for rigorous validation of new vehicle in very short period and requires to map customer usage pattern in least possible time. This work is based on an extension of internet of things (IOT), which provides a tool of capturing vehicle duty cycle by using combination of analog and digital sensors with appropriate ADC. The system is enabled with algorithm/ coded to log result, whenever measured physical parameter goes above/below predetermined level. The work involves implementation of an auto start and auto shutdown of the system based on vehicle ignition. Thus, this paper presents a system that is capable of continuous, real time recording and edge computing (auto post processing) physical quantity and ensures complete elimination of human interface, thereby enabling Remote Data Acquisition, Analysis and Reporting system (Proposed system). The proposed system is fit and forget and cost-effective solution, it can be fitted in any number of vehicles to acquire data for large number of kilometers to map system level usage pattern. Against the conventional method with limited kilometers of data to map customer pattern. The present work is an implementation of Remote Data Acquisition, Analysis and Reporting system in measurement of required vehicle parameters of temperature and humidity in field working conditions.
{"title":"Development and Implementation of Remote Duty Cycle Data Acquisition and Analysis","authors":"Sathish Kumar P, Kumar P, Dayalan P","doi":"10.37285/ajmt.1.2.5","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.5","url":null,"abstract":"In the competitive automotive industry, launch of a new vehicle has become a norm to stay ahead, also the vehicle manufacturers are competing in terms of increased warranty on the new launch. Hence it is imperative for rigorous validation of new vehicle in very short period and requires to map customer usage pattern in least possible time. This work is based on an extension of internet of things (IOT), which provides a tool of capturing vehicle duty cycle by using combination of analog and digital sensors with appropriate ADC. The system is enabled with algorithm/ coded to log result, whenever measured physical parameter goes above/below predetermined level. The work involves implementation of an auto start and auto shutdown of the system based on vehicle ignition. Thus, this paper presents a system that is capable of continuous, real time recording and edge computing (auto post processing) physical quantity and ensures complete elimination of human interface, thereby enabling Remote Data Acquisition, Analysis and Reporting system (Proposed system). The proposed system is fit and forget and cost-effective solution, it can be fitted in any number of vehicles to acquire data for large number of kilometers to map system level usage pattern. Against the conventional method with limited kilometers of data to map customer pattern. The present work is an implementation of Remote Data Acquisition, Analysis and Reporting system in measurement of required vehicle parameters of temperature and humidity in field working conditions.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126927428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irrespective of specific applications, the Small Commercial Vehicles (SCV) are always subjected to severe working conditions, especially the front wheels experience higher loads than design intended due to higher overloading by customers, driver abuse and frequent brake applications. The front axle wheels fasten system plays a key role for safety of the vehicle and pedestrian. The wheel separation can lead to serious injuries to passengers of the vehicle and pedestrian or from another vehicle maneuvering including fatalities. In this project investigation, the causes that promote failure of front axle wheels fasten system and subsequent wheels separation of SCV is analyzed carefully. Metallurgical analysis of the failed fasten system shows that it is characterized by a series of synergetic steps that include plastic deformation of nuts and studs caused due to disproportionate torque tightening practices. Also, the effect of other external factors that lead to deterioration of stud fatigue life such as road camber and driver abuse are analyzed. Based on this promise, the present investigation deals with detailed analysis of the root causes contributing such failures are analyzed and discussed in this paper. This study would help the fellow designers to select optimized fastening system considering all the parameters influencing wheel separation due to stud failures for SCV, passenger vehicles and heavy duty trucks.
{"title":"Failure Analysis of Front Axle Wheel Studs in Small Commercial Vehicles","authors":"Mahadevan Pichandi, Jagadeesh Selvaraj","doi":"10.37285/ajmt.1.2.2","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.2","url":null,"abstract":"Irrespective of specific applications, the Small Commercial Vehicles (SCV) are always subjected to severe working conditions, especially the front wheels experience higher loads than design intended due to higher overloading by customers, driver abuse and frequent brake applications. The front axle wheels fasten system plays a key role for safety of the vehicle and pedestrian. The wheel separation can lead to serious injuries to passengers of the vehicle and pedestrian or from another vehicle maneuvering including fatalities. In this project investigation, the causes that promote failure of front axle wheels fasten system and subsequent wheels separation of SCV is analyzed carefully. Metallurgical analysis of the failed fasten system shows that it is characterized by a series of synergetic steps that include plastic deformation of nuts and studs caused due to disproportionate torque tightening practices. Also, the effect of other external factors that lead to deterioration of stud fatigue life such as road camber and driver abuse are analyzed. Based on this promise, the present investigation deals with detailed analysis of the root causes contributing such failures are analyzed and discussed in this paper. This study would help the fellow designers to select optimized fastening system considering all the parameters influencing wheel separation due to stud failures for SCV, passenger vehicles and heavy duty trucks.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129979777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper aims to understand the different injury mechanisms involved with traumatic Bilateral Facet Dislocation (BFD) and fracture of the cervical spine. The intent is to demonstrate and elucidate tensile and compression induced injury mechanisms producing BFD by employing real-world crash investigations in association with all the past laboratory testing and studies done by numerous researchers. The study indicates that in a frontal crash scenario, maintaining the position of the shoulder belt is paramount, and any migration towards the base of the neck allows the fulcrum formation that amplifies distractive moments on the neck producing BFD. Similarly, in a rollover crash scenario, roof intrusion magnitude, and its rate along with roof deformation pattern can impose a rotational constraint on the head and plays a vital role in producing BFD. Roof design must address the formation of pocketing in the roof due to deformations imposing rotational head constraint exposing the neck to buckling and subsequent BFD as the roof intrusion continues.
{"title":"Bilateral Facet Dislocations With and Without Head Impact Sustained by Restrained Occupants","authors":"Dr. Chandrashekhar K. Thorbole","doi":"10.37285/ajmt.1.2.1","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.1","url":null,"abstract":"This paper aims to understand the different injury mechanisms involved with traumatic Bilateral Facet Dislocation (BFD) and fracture of the cervical spine. The intent is to demonstrate and elucidate tensile and compression induced injury mechanisms producing BFD by employing real-world crash investigations in association with all the past laboratory testing and studies done by numerous researchers. The study indicates that in a frontal crash scenario, maintaining the position of the shoulder belt is paramount, and any migration towards the base of the neck allows the fulcrum formation that amplifies distractive moments on the neck producing BFD. Similarly, in a rollover crash scenario, roof intrusion magnitude, and its rate along with roof deformation pattern can impose a rotational constraint on the head and plays a vital role in producing BFD. Roof design must address the formation of pocketing in the roof due to deformations imposing rotational head constraint exposing the neck to buckling and subsequent BFD as the roof intrusion continues.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121061489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There is a strong interaction between air and vehicle components. Aerodynamics plays a significant role in a vehicle's fuel efficiency. The contact patch load between the tire and road is directly related to the vehicle load. In this research, the lift forces generated due to the additional wing attached to the car model with different spans and heights of the wing location from the car body is considered for study. The loads due to change in Angle of Attack (AOA) and their effect on the tire loads are studied. The upward vertical force produced from aerodynamic loads reduces the wheel load of the car virtually. A tire's coefficient of friction would decrease with upward vertical force. This balance load implies that a lightweight car would make more efficient use of its tires than a heavier car. ANSYS Fluent is used for the Computational Fluid Dynamics (CFD) study. The validation of airflow characteristics, lift and drag forces from simulations are done with wind tunnel testing data. Varying the angle of attack, wingspan, height between the car and the wing's lower surface, one can increase the capacity of the payload by 10% or fuel efficiency by 10% to 20%.
{"title":"Aerodynamic Effect on Stability and Lift Characteristics of an Elevated Sedan Car","authors":"Amrutheswara Krishnamurthy, Dr.Suresh Nagesh","doi":"10.37285/ajmt.1.2.6","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.6","url":null,"abstract":"There is a strong interaction between air and vehicle components. Aerodynamics plays a significant role in a vehicle's fuel efficiency. The contact patch load between the tire and road is directly related to the vehicle load. In this research, the lift forces generated due to the additional wing attached to the car model with different spans and heights of the wing location from the car body is considered for study. The loads due to change in Angle of Attack (AOA) and their effect on the tire loads are studied. The upward vertical force produced from aerodynamic loads reduces the wheel load of the car virtually. A tire's coefficient of friction would decrease with upward vertical force. This balance load implies that a lightweight car would make more efficient use of its tires than a heavier car. ANSYS Fluent is used for the Computational Fluid Dynamics (CFD) study. The validation of airflow characteristics, lift and drag forces from simulations are done with wind tunnel testing data. Varying the angle of attack, wingspan, height between the car and the wing's lower surface, one can increase the capacity of the payload by 10% or fuel efficiency by 10% to 20%.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126876337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nagmani, Debanjana Pahari, Ashwani Tyagi, Dr. Sreeraj Puravankara
Rechargeable batteries are an integral part of all types of electric vehicles (EVs). Batteries must contain higher energy-power densities and longer cycle life for an EV system. Lead-acid batteries, Nickel-metal hydride batteries, and Lithium-ion batteries (LIBs) have been employed as charge storage in EV systems to date. Lead-acid batteries and Nickel-metal hydride batteries were deployed in EVs by General Motors in 1996. However, the low specific energy in Lead-acid batteries (34 Whkg-1) and high self-discharge (12.5% per day at r.t.) in Nickel-metal hydride batteries have marked these batteries obsolete in EV applications. LIBs currently occupy most of the EV market because of their high specific power (~130-220 Whkg-1) and a low selfdischarge rate (~5% per month). The current technological maturity and mass production in LIBs have reduced the overall battery cost by ~98% in the last three decades, reaching an average value of $140 kWh-1 in 2021. Although a game-changer in battery technologies, LIBs encounter various challenges: high cost, low safety, less reliability, and immature infrastructure despite environmental benignness. Overcharging and overheating of LIBs can cause thermal runway leading to fire hazards or explosion. Declining Liresources also raise concerns regarding the reliability and shelf-life of LIB technology. Hence, a critical assessment of Li-ion chemistries is essential to comprehend the potential of LIBs in electric mobilities and to realize the prospects in EVs.
{"title":"Lithium-Ion Battery Technologies for Electric Mobility – State-of-the-Art Scenario","authors":"Nagmani, Debanjana Pahari, Ashwani Tyagi, Dr. Sreeraj Puravankara","doi":"10.37285/ajmt.1.2.10","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.10","url":null,"abstract":"Rechargeable batteries are an integral part of all types of electric vehicles (EVs). Batteries must contain higher energy-power densities and longer cycle life for an EV system. Lead-acid batteries, Nickel-metal hydride batteries, and Lithium-ion batteries (LIBs) have been employed as charge storage in EV systems to date. Lead-acid batteries and Nickel-metal hydride batteries were deployed in EVs by General Motors in 1996. However, the low specific energy in Lead-acid batteries (34 Whkg-1) and high self-discharge (12.5% per day at r.t.) in Nickel-metal hydride batteries have marked these batteries obsolete in EV applications. LIBs currently occupy most of the EV market because of their high specific power (~130-220 Whkg-1) and a low selfdischarge rate (~5% per month). The current technological maturity and mass production in LIBs have reduced the overall battery cost by ~98% in the last three decades, reaching an average value of $140 kWh-1 in 2021. Although a game-changer in battery technologies, LIBs encounter various challenges: high cost, low safety, less reliability, and immature infrastructure despite environmental benignness. Overcharging and overheating of LIBs can cause thermal runway leading to fire hazards or explosion. Declining Liresources also raise concerns regarding the reliability and shelf-life of LIB technology. Hence, a critical assessment of Li-ion chemistries is essential to comprehend the potential of LIBs in electric mobilities and to realize the prospects in EVs.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126914768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Avadhoot Kittur, Dikhsita Choudhary, Dr. Robert Michael Slepian
With the growing demand of electric vehicles, design of circuit protection devices is now an important consideration in automobile industry. Modern day circuit protection devices have been constantly undergoing miniaturization due to requirement of minimizing the foot print for use in electrical vehicles and aerospace applications. This size reduction makes thermal management one of the most important aspects of their design. Use of numerical model to predict heat transfer can significantly reduce the cost and time required in testing physical prototypes. In this paper, three different approaches for numerically predicting temperature rise of circuit breakers are discussed and compared from the point of view of accuracy and computational effort. The three methods are 1) Finite volume based analysis in which conjugate heat transfer inside and outside the breaker is modelled by solving Navier-Stokes equations 2) Finite element based heat conduction model in which convection is modelled as boundary condition instead of solving for fluid motion, and 3) Thermal network based model which uses electrical analogy of heat transfer to solve a thermal resistance network. In the first two iterative models mentioned above, heat generation from current-carrying parts is calculated by solving Maxwell’s equations of electromagnetics by Finite element method. Eddy current losses and temperature dependence of electrical conductivity is considered in the calculation of heat loss. In all three methods, electrical and thermal contact resistances are added at appropriate locations based on analytical calculations. All three methods have been validated with temperature rise test results. In this paper, the heat loss and temperature of a molded case circuit breaker have been predicted by all three methods discussed above. It is observed that the Finite volume-based method is the most accurate amongst the three methods. It can computationally predict air motion and air temperature at critical locations. However, this additional accuracy comes at the cost of added effort in terms of additional mesh count and computation. The Finite elementbased method gives good accuracy but does not predict air temperature. The analytical network-based model is less accurate compared to other methods and relies on product expertise and experience. Based on the study, the following recommendations are made:1) The finite element-based method is best suited to evaluate designs which do not alter flow pattern significantly 2) The finite volume method is recommended to evaluate effect of flow altering design changes 3) The network-based model is recommended for initial evaluation of correct cross sections of current carrying members.
{"title":"Comparison of Numerical Methods for Thermal Performance Evaluation of Circuit Protection Devices in EV Application","authors":"Avadhoot Kittur, Dikhsita Choudhary, Dr. Robert Michael Slepian","doi":"10.37285/ajmt.1.2.9","DOIUrl":"https://doi.org/10.37285/ajmt.1.2.9","url":null,"abstract":"With the growing demand of electric vehicles, design of circuit protection devices is now an important consideration in automobile industry. Modern day circuit protection devices have been constantly undergoing miniaturization due to requirement of minimizing the foot print for use in electrical vehicles and aerospace applications. This size reduction makes thermal management one of the most important aspects of their design. Use of numerical model to predict heat transfer can significantly reduce the cost and time required in testing physical prototypes. In this paper, three different approaches for numerically predicting temperature rise of circuit breakers are discussed and compared from the point of view of accuracy and computational effort. The three methods are 1) Finite volume based analysis in which conjugate heat transfer inside and outside the breaker is modelled by solving Navier-Stokes equations 2) Finite element based heat conduction model in which convection is modelled as boundary condition instead of solving for fluid motion, and 3) Thermal network based model which uses electrical analogy of heat transfer to solve a thermal resistance network. In the first two iterative models mentioned above, heat generation from current-carrying parts is calculated by solving Maxwell’s equations of electromagnetics by Finite element method. Eddy current losses and temperature dependence of electrical conductivity is considered in the calculation of heat loss. In all three methods, electrical and thermal contact resistances are added at appropriate locations based on analytical calculations. All three methods have been validated with temperature rise test results. In this paper, the heat loss and temperature of a molded case circuit breaker have been predicted by all three methods discussed above. It is observed that the Finite volume-based method is the most accurate amongst the three methods. It can computationally predict air motion and air temperature at critical locations. However, this additional accuracy comes at the cost of added effort in terms of additional mesh count and computation. The Finite elementbased method gives good accuracy but does not predict air temperature. The analytical network-based model is less accurate compared to other methods and relies on product expertise and experience. Based on the study, the following recommendations are made:1) The finite element-based method is best suited to evaluate designs which do not alter flow pattern significantly 2) The finite volume method is recommended to evaluate effect of flow altering design changes 3) The network-based model is recommended for initial evaluation of correct cross sections of current carrying members.","PeriodicalId":294802,"journal":{"name":"ARAI Journal of Mobility Technology","volume":"11 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120847958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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