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Occupant Controlled Ventilation

Mahindra & Mahindra, Ltd.-Priyanka Marudhavanan
  • Technical Paper
  • 2019-28-2461
To be published on 2019-11-21 by SAE International in United States
Keywords-Coolant,Ventilation Research and/or Engineering Questions/Objective: Number of Occupants is the major parameter when we consider Air Conditioning System. The number of person who stays in the room may vary in the same way the person who travels in the automobile also vary throughout the distance. This is more prevalent in transportation system like bus, train and where lot of people will travel together and where dropping station in the vehicle is too frequent.In this type,operating A.C has to be varied Methodology: . Instead the number count in the vehicle will be monitored from time to time. Based on the number of count, the cabin has to be cooled or heated and accordingly corresponding power has to be drawn by the compressor from the engine. This human count can be detected based on the number of CO2 sensor located in the cabin. the amount of fresh air that should be added to a cabin can be controlled by a carbon dioxide level transmitter. When CO2 levels go up, fresh air is added until the CO2 levels…

Body Structure Strength Of Sleeper Coaches During Rollover Test As Per AIS 119

International Centre For Automotive Tech.-Gopal Singh Rathore
  • Technical Paper
  • 2019-28-2567
To be published on 2019-11-21 by SAE International in United States
Bus passenger safety has always been a concern considering various impacts like side impact, front impact, rollover etc. happening in real life scenarios. Various standards have been formulated for simulating these conditions and with respect to rollover, standards like ECE-R66 are being used to understand the superstructure strength. In India, we have AIS-052 (bus body code) and AIS-031 specific for bus rollover testing. AIS-119 has been published for rollover testing of sleeper coaches with modifications in the survival space creation in sleeper coaches for berths. With physical testing being more expensive, CAE simulations are being considered as vital option which also helps in design modification in a lesser time. This paper discusses the scope of numerical simulation of sleeper coach rollover using an explicit dynamic solver RADIOSS to understand the structure deformations, survival space clearances/intrusions. The paper will describe the procedure for the numerical simulation starting from the CAD development, geometry clean up, meshing techniques, element formulations, CG measurement, input deck set up till the post processing of results. In order to validate the numerical…

Impact of wheel-housing on aerodynamic drag and effect on energy consumption on an electric bus body

ARAI Academy-Amitabh Das, Yash Jain
Automotive Research Association of India-Mohammad Rafiq Agrewale, Kamalkishore Vora
  • Technical Paper
  • 2019-28-2394
To be published on 2019-11-21 by SAE International in United States
Role of Wheel and underbody Aerodynamics of vehicle in the formation of drag forces is detrimental to the fuel (energy) consumption during the course of operation at high velocities. This paper deals with the CFD simulation of the flow around the wheels of a bus with different wheel housing arrangements. Based on benchmarking, a model of a bus is selected and analysis is performed. The aerodynamic drag coefficient is obtained and turbulence around wheels is observed using ANSYS Fluent CFD simulation for different combinations of wheel-housing- at the front wheels, at the rear wheels and both in the front and rear wheels. The drag force is recorded and corresponding influence on energy consumption of a Bus is evaluated mathematically. A comparison is drawn between energy consumption of bus body without wheel housing and bus body with wheel housing. The result shows a significant reduction in drag coefficient and fuel consumption. Keywords: Wheel-housing, Drag Coefficient, CFD Simulation, Bus, Energy consumption

EMC challenges & solutions for Electric Buses

ICAT-Enoch Eapen
  • Technical Paper
  • 2019-28-2503
To be published on 2019-11-21 by SAE International in United States
EMC challenges & solutions for Electric Buses Enoch Eapen, Devender Kumar and Madhusudan Joshi International Centre for Automotive Technology, Manesar Electric buses are talk of the town in India with Government pushing the implementation of E-mobility in general and for public transportation in particular. However due to high voltages and complex power electronics design, it often becomes difficult to deal with EMC related non-compliances. ICAT being largely experienced in the EMC testing and validation of E-buses, would like to present the various EMC challenges and the solutions related to E-buses. In this paper we would share three case studies where the EMC issues related to E-buses were mitigated by either introducing simple changes to the existing design or through large/small modification. We believe that the proposed case studies would help the bus manufactures to understand the real EMC issues closely and implement the solutions accordingly prior to submitting for final certification to the test agencies leading to lesser cost impact and shorter validation time.

Effect of variable payload on Vehicle dynamics of Passenger buses in Indian usage conditions

VE Commercial Vehicle-Abhishek pyasi
VE Commercial Vehicles, Ltd.-ABHOY CHANDRA
  • Technical Paper
  • 2019-28-2411
To be published on 2019-11-21 by SAE International in United States
A high impetus from Government on road infrastructure development, is giving a fillip to passenger CV space. This has resulted in making the passenger CV segment lucrative enough, thereby pulling in many operators in the business. The quality of road has immensely improved over a decade, as a result of which the average speed and hence the quantum of distance covered by passenger buses has increased significantly. People are preferring to travel in buses over trains, owing to at par ticket cost, high availability, reduced travel time and also improved level of comfort. Aligned to the market need and the trend, OEM's are offering buses with capable powertrains to cater the need of speed, reduced trip time as well as a lot of attention is also being paid to tune in the comfort level for long hauls. A big chunk of passenger travel is catered by the bus operators especially during major festivals in India. However, the passenger demand is not so consistent in this industry due to seasonality and hence is the operator earnings,…

Noise & Vibration challenges in an Electric Vehicle (Bus), its effect and possible reduction techniques

International Centre For Automotive Tech.-Ikshit Shrivastava
  • Technical Paper
  • 2019-28-2493
To be published on 2019-11-21 by SAE International in United States
Ikshit Shrivastava1, Kiranpreet Singh2 1,2 International Centre for Automotive Technology (ICAT), Gurugram, India Introduction: Noise and Vibrations is a vast field of study and has been a constant challenge to Acousticians and designers. IC engines have been in existence since almost 125 years and have given enough room & time to acousticians and engineers to develop materials and tune powertrains to minimize Noise and Vibrations from vehicles. With the advent of technology to evolve alternate fueled powertrains to reduce emissions emitted by IC engines, lot of research is being carried out to develop powertrains particularly in the area of Hybrids & Electrics. Substantial investments are being made by OEMs worldwide on researching xEV domain to tap new motor/ battery technologies for vehicles. Since the technology in xEVs is majorly different, the problems associated with them are also different. IC Engines were known to create Noise in running condition, whereas Electric Vehicles are seen as no noise emitting products. The challenge is not just to create a vehicle with zero noise and vibrations inside of the…

Passenger "Sleeper Bus" Structure, an Optimization Study using Finite Element Analysis

JCBL, Ltd.-Yaseen Khan
JCBL,Ltd.-Priyanka Bhola
  • Technical Paper
  • 2019-28-2537
To be published on 2019-11-21 by SAE International in United States
ABSTRACT Sleeper buses are increasingly used as connectivity between cities and remote areas with sleeping comfort for passengers. During the normal operation, the bus body is subjected to several loads, external loads from the road (i.e. crossing over a speed bump, breaking & cornering). Moreover, there is a substantial possibility that these loads may lead to a structural failure. Hence, it is necessary to determine stresses occurred in the bus body to ensure its integrity under these driving scenarios. During the accident, rollover/front/rear/side impact, energy absorbing capacity of bus body structure is crucial for safety of passengers. The objective of this study is to reduce weight of bus structure while maintaining cost & safety as constraint. 3D Model prepared in NX and finite element model created in hypermesh ,LS-dyna/optistruct used as solver and post processing done in hyperview. In this study, fully loaded bus with passengers as well as maximum language mass, considered. The present study is based on the finite element analysis and design optimization of passenger sleeper bus. Number of iterations in stiffness…

Electric Commercial Vehicles And Charging Solutions

Electromobility-Murlidhar Shrivallabha Phatak
Siemens-Manfred Schmidt, Amit Kekare
  • Technical Paper
  • 2019-28-2476
To be published on 2019-11-21 by SAE International in United States
Objective : Objective of the paper is to acquaint the audience with the concept of electric vehicles, Powertrain components used in an electric bus, Siemens contribution to the field of Electromobility, Typical configurations used in an electric bus, challenges and current limitations, emerging Technologies, future, how to address the future charging infra requirement. Methodology : The subject shall be discussed with the audience through a presentation coupled with Explanation by the presenter. The topic shall be opened with the concept of electromobility followed By history of electromobility at Siemens, contribution to the field of electro mobility, typical configurations of electric vehicles, Advantages of electric vehicles vis a vis conventional diesel buses, typical configurations of an electric bus, feasibility of electric buses for various transport services. Comparison of induction motor Vs. PEM motor (permanent magnet motor) technology, Digitalization And Siemens contribution in the field of digitalization, Future of electric mobility, use of alternate Fuels, charging infrastructure and solutions, technical details. Different charging infrastructure solutions and their pro and cons will be discussed in an open manner.…

Premium Buses Airconditioning System Development and Verification

Volvo Buses-Ganesh Kowndinya, Asish Mohanty
  • Technical Paper
  • 2019-28-0020
To be published on 2019-10-11 by SAE International in United States
Airconditioning has become a prominent picture in premium segment buses over a decade of time. It has undergone many changes as and when the demand for passenger comfort in public transport industry has raised. Airconditioning is a critical topic influencing the passenger comfort in most of the mass transit vehicles. Transit buses operate in diversified weather conditions especially in country like India across the year, which impose challenge to a single airconditioning system fitted onto bus to provide right airconditioning so the passenger comfort will not be compromised. Airconditioning system has positively increased the comfort level of passengers irrespective of hauling distance or its application for city or intercity transits. Selecting a right airconditioning system for bus application plays a major role in addressing the passenger comfort topic in a broader perspective. This paper discuss on those important area's which directly impacts the passenger comfort in transit application. This paper discuss in detail onto different stages in Airconditioning system selection process, development methods and verification process to evaluate the system against stated requirement while keeping…

Aerodynamic Drag Reduction of a Intercity Bus through surface modifications- A Numerical Simulation

Mahindra & Mahindra, Ltd.-Mathialagan Velshankar
SRM Institute of Science and Technology-Sundararaj Senthilkumar, Budda Thiagarajan Kannan
  • Technical Paper
  • 2019-28-0045
To be published on 2019-10-11 by SAE International in United States
The maximum power produced by the Engine is utilized in overcoming the Aerodynamic resistance while the remaining has been used to overcome rolling and climbing resistance. Increasing emission and performance demands paves way for advanced technologies to improve fuel efficiency. One such way of increasing the fuel efficiency is to reduce the aerodynamic drag of the vehicle. Buses emerged as the common choice of transport for people in India. By improving the aerodynamic drag of the Buses the diesel consumption of a vehicle can be reduced by nearly about 10% without any upgradation of the existing engine. Though 60 to 70 % of pressure loads act on the frontal surface area of the buses, the most common techniques of reducing the drag in buses includes streamlining of the surfaces, minimizing underbody losses, reduced frontal area, pressure difference between the front & rear area and minimizing of flow separation & wake regions. As city buses won't have cargo storage constraints roof optimization can be done to reduce the drag coefficient value. A base model of the…