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ARAI, India

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ARAI, India
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Chandra Sekhar J.,ARAI ACADEMY | Rajamanickam R.,A R A i | Ramachandran E.,A R A i | Karanth N.V.,A R A i
SAE Technical Papers | Year: 2013

Modal analysis is a specialized tool which has been used for many years to reliably estimate various parameters such as natural frequency, mode shape and damping. Since these parameters have direct relevance to the behavior of any component or structure and the resultant vibrations, the methods used for evaluation of these have been taken up as a part of this project. MATLAB is a platform that serves analysis purpose and offers many advantages over dedicated, menu driven systems. Open function assure flexibility and possibility to modify functions for specific needs and also providing traceability and quality assurance. The current paper targets to make a comparative evaluation of various modal parameter estimators using existing MATLAB tools for determining modal parameters for simple structures. FRF measurements on simple structures are carried out and the data is processed using MATLAB run parameter estimators. The computed results are compared and advantages and limitations of the estimators are discussed. © 2013 SAE International.


Gode R.,ARAI Academy | Goswami A.,VE Commercial Vehicles Ltd | Barman J.,VE Commercial Vehicles Ltd | Lakhlani H.,VE Commercial Vehicles Ltd
SAE Technical Papers | Year: 2015

Air motion in a cylinder in a compression ignition engine affects on mixing of air-fuel, quality of combustion and emission produced. With upcoming stringent norms for diesel engines, it is necessary to enhance air-fuel mixing for proper combustion. Swirl and tumble are forms of air motion. Swirl is a rotational motion of a bulk mass within cylinder. Swirl is generated by shaping and countering intake manifold and valve ports. Swirl enhances air-fuel mixing and helps to spread flame-front during combustion. The objective of this paper is to analyze the impact of different swirl ratios on NOx and soot emission characteristics inside the cylinder of a DI Diesel engine. The effects of different geometrical parameters of helical port were studied and the swirl ratios are optimized by optimizing the geometrical parameter of helical port. This can be done by different manufacturing, polishing and grinding processes. The designed inlet port were then validated by measuring swirl on AVL paddle wheel anemometer and the experiments were conducted on these inlet ports of different swirl ratios and validate the NOx and soot emissions as per emission norms BS IV. Positive results have been observed and the data has been shared in paper. Copyright © 2015 SAE International and Copyright © SAEINDIA.


Stechert C.,TU Braunschweig | Vora K.C.,ARAI Academy
SAE Technical Papers | Year: 2013

India already has the highest concentration of megacities and urban growth continues. Together with an increasing need for individual mobility in particular, the Indian market demands new vehicle concepts. German lower-Saxony research centre of Automotive Engineering (NFF) and The Automotive Research Association of India (ARAI) together with representatives from the automotive industry develop a research roadmap to satisfy the future demand for metropolitan cars. Copyright © 2013 SAE International and Copyright © 2013 SIAT, India.


Talegaonkar S.,ARAI Academy | Agrewale M.R.B.,Automotive Research Association of India | Chhaganlal Vora K.,ARAI Academy
SAE Technical Papers | Year: 2016

The Exhaust Noise is one of the major noise pollutants. It is well-known that for higher noise reduction, the engine has to bear high back pressure. For a race car, back-pressure plays a major role in engine's performance characteristics. For a given condition of engine rpm & load, conventional muffler has a fixed value of back-pressure and noise attenuation. Better acceleration requires low back-pressure, but the exhaust noise should also be less than the required (Norm) value (110 dBA). This contradicting condition is achieved here by using a 'Butterfly Valve' in this novel exhaust muffler. The butterfly valve assumes 2 positions i.e. fully open & fully closed. When the valve is fully closed, the noise reduction will be higher, but the back-pressure will also shoot up. When open, noise reduction will be less and so the back-pressure. So, when better performance is required, the valve is opened and back-pressure is reduced. The muffler is designed for a 4 cylinder 600 cc engine. The sound transmission loss (STL), which is the measure of effectiveness of the muffler, is also verified experimentally. The reduction in the back pressure at 11000 engine rpm is around 40% with open valve, as compared closed valve condition. The increase in STL, with closed valve, is around 15∼20 dB higher when compared to open valve condition. Copyright © 2016 SAE International.


Tathe S.R.,CoEP ARAI Academy | Wani K.P.,ARAI Academy
SAE Technical Papers | Year: 2013

Whole body vibration deals with the biodynamic responses of human body in various postures. Vertical vibration exposure in sitting posture is common situation encountered while driving vehicle or riding motorcycle. We have chosen Wan & Schimmel's 4 DOF biodynamic model for this study by referring the goodness of fit results for various models available in the literature. A single degree of freedom model of motorcycle is used for analysis of whole body vibration on two wheeler. We have neglected pitch, yaw movements of two wheeler for purpose of simplicity. Whole body vibration analysis for human body in sitting posture is described by three terms i.e. Seat to Head Transmissibility (STH), Driving point impendence (DPM) & apparent mass (AP). In order to analyze human response on motorcycle Road to head (RTH), Road to lower torso (RTLT), Road to viscera (RTV), Road to upper torso (RTUT) responses are calculated for different motorcycle suspension natural frequencies. Simulation of biodynamic model is carried in MATLAB which shows close match with experimental results from literature. Analysis shows that peak values occur at 3.97 Hz, 6.77 Hz & 3.24 Hz for STH, DPM & AP respectively. For 4 Hz suspension natural frequency of motorcycle, most severe RTH, RTUT, RTV, RTLT responses are noted. These responses are severe in the two wheeler suspension natural frequency range of 3.5 Hz to 5.5 Hz. This study will help in better design & also in improving the ride & handling performance of two wheeler. © 2013 SAE International.


John N.A.,ARAI Academy | Sherki M.,ARAI Academy | Patil S.A.,ARAI Academy
SAE Technical Papers | Year: 2016

New generation automobiles are equipped with power windows which eases the passenger's effort in moving the vehicle windows up and down. Many of them are stuffed with advanced features like automatic up/down option for ensuring functionality with a single press of the switch. Even though it adds comfort to driver & passenger, inadvertent use of power window can be fatal if a person's body part gets trapped inside. An effective solution for this problem is anti-pinch mechanism, which releases the object safely just when it gets trapped. It detects the object trapped and immediately moves the window down so that trapped object will get released easily. The anti-pinch algorithm used in this project is based on the "Method of Monitoring Movable Element", method monitor traveling distance of a power window pane. In order to achieve this different from conventional techniques we are using Ultrasonic sensor. The anti-pinch technology of power window has to meet standards issued by EU and United States. The maximum force a power window is allowed to exert on any object is 100N. Compliance with this limit must be monitored and enforced in a range of 4mm to 100mm from the top window frame, which is successfully meet by prototype designed. The goal of this project is to provide ultimate protection from power window injuries by implementing this simple & effective safety system to vehicles which are already running on road. Compactness & independent functionality ensures great compliance of this accessory with existing power windows. Copyright © 2016 SAE International.


Patil I.,College of Engineering, Pune | Wani K.P.,ARAI Academy
SAE Technical Papers | Year: 2015

The three main objectives that a suspension system of an automobile must satisfy are ride comfort, vehicle handling and suspension working space. The aim of this paper is to design and analyze the semi active suspension system models using skyhook, ground hook and hybrid control method. The two degree of freedom (2 DOF) quarter car model is used for analysis of vehicle body displacement, vehicle acceleration and suspension working space and dynamic tire deflection. Simulation of semi active control models are carried out in MATLAB SIMULINK which describes performance of passive system, skyhook on-off and continuous control, ground hook control and hybrid control methods. Time response analysis shows that, for road bump excitation of 70mm vertical displacement, skyhook on-off control improves ride comfort for the results of maximum peak to peak body displacement with 27.53% improvement than that of the passive suspension model. While ground hook control improves vehicle stability for the results of maximum peak to peak wheel displacement and dynamic tire deflection which has improvement of about 7.69% and 23.07% respectively when compared with passive suspension model. Where hybrid control improves ride comfort as well as road stability depending upon the controller gain. The semi-active quarter car simulation is enhanced with 3-D animation of car going on bump created in VRML tool in MATLAB. This study will help in better design and also in improving the ride comfort and vehicle handling performance of a four wheeler. Copyright © 2015 SAE International and Copyright © SAEINDIA.


Gurusamy S.K.,Daimler India Commercial Vehicles Ltd. | Rajagopalan C.,ARAI Academy | Sateesh Kumar R.,Daimler India Commercial Vehicles Ltd. | Ashok B.,Vellore Institute of Technology
SAE Technical Papers | Year: 2015

In present commercial vehicles, the cranking torque required for a heavy duty compression ignition engine is very high. This results in higher durability and reliability requirement of cranking system components and also makes it cumbersome to implement start-stop micro hybrid feature which requires more number of cranking cycles in lifetime. Hence higher capacity starter motor and battery is being used for implementing start-stop feature. However this would result in cost and packaging issues. In order to implement start-stop feature maintaining the same starter motor and battery capacity, the cranking energy demand of the engine needs to be reduced. Studies conducted shows that the major source of breakaway torque is the work done in compression stroke during a starting cycle. Hence the concept of decompression which is used only in smaller capacity engines at present was benchmarked and modified to create an energy venting actuator for a heavy duty 4 cylinder engine which would release the compression pressure momentarily during starting. The cranking torque requirement for the engine was analyzed with and without the decompression device and an experimental reduction of 29% in starting current requirement was obtained. Copyright © 2015 SAE International and Copyright © SAEINDIA.


Jain P.,ARAI Academy | Kulkarni V.,ARAI Academy | Kulkarni S.,Mahindra and Mahindra Ltd | Mahajan R.,Mahindra and Mahindra Ltd
SAE Technical Papers | Year: 2016

There are significant geometrical as well as operational parameters which affect the emission performance of a diesel engine. In this work, various important engine variables are selected for optimization. The objective of this work is to satisfy BS III norms, that too, with a healthy margin. Among the selected variables, swirl is a complex variable to control, and that itself depends on number of geometrical and operational parameters. Chamfer angle of the valve seat is modified to vary swirl ratios, actual swirl performance test is done. Further, CFD and analytical analysis is done on various geometrical parameters of intake port and important parameters affecting swirl were identified. Thus, by the above exercise three optimum swirl ratios were selected for design of experiments. Engine variables selected for optimization are swirl ratio, fuel injection timing, nozzle orifice (K and KS type) and turbocharger (waste gate and free float). L9 Orthogonal array was formed consisting of 9 experiments, in which each variable was varied at different levels. Standard Engine Steady state Cycle (ESC) was performed for each experiment. Analytical tools of Taguchi method like Analysis of Means, Signal to Noise ratio and Analysis of Variance was applied on the obtained experimental results and an optimum setting was found. Fuel injection timing, swirl ratio and nozzle orifice were found out to be significant parameters affecting emissions. The optimum setting gave a good margin for PM, CO, HC and NOx at 20%, 65.23%, 90.9% and 9% respectively, from BS III norms. Copyright © 2016 SAE International.


Gopi Krishnan N.S.,ARAI Academy | Wani K.P.,ARAI Academy
SAE Technical Papers | Year: 2015

This paper describes the design and development of a prototype parallel hybrid electric two-wheeler vehicle. A unique transmission system is designed, developed and integrated into a two-wheeler with conventional manual transmission system. The vehicle runs on a petrol engine coupled with an electric motor in parallel drive configuration. The vehicle has three basic modes of operation - engine mode, electric mode, hybrid switching mode. Two optional modes are also possible - Regenerative braking mode and Continuous assistance mode. Apart from these, the vehicle has an independent gear box set for the electric motor, meant for three other modes of operation - low speed (high torque), medium speed and high speed operations suitable for high gradient, city and highway conditions respectively when in electric mode. The maximum speed target in electric mode is 25kmph in city drive and 40kmph in highway with a range of 50km per charging in electric mode. The range targeted is 100km for a run in hybrid mode. An 80cc grade gasoline two-wheeler is chosen for the purpose. The vehicle is twelve year old and uses two-stroke cycle. The vehicle is successfully tested to meet the projected target. Throughout the course of the work emphasis is given on safety, simplicity and reliability to the possible extent. Copyright © 2015 SAE International and Copyright © SAEINDIA.

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