Roy H.K.,University of Warwick |
Roy H.K.,TVS Motor Company |
McGordon A.,University of Warwick |
Jennings P.A.,University of Warwick
IEEE Transactions on Vehicular Technology | Year: 2014
Hybrid electric vehicles (HEVs) are considered to be one of the energy-efficient technologies for near-term sustainability of the transportation sector. Over the years, research has focused on improving fuel economy (FE) for a given drive cycle, but FE variability over a realistic range of real-world driving patterns has been generally overlooked, and this can lead to FE benefits not being fully realized in real-world usage. No systematic methodology exists to reduce FE variability by design optimization of powertrain components. This study proposes a methodology of powertrain component optimization to reduce the FE variability due to variations in driving patterns. In the proposed methodology, powertrain components are optimum over a range of driving patterns of different traffic conditions and driving styles simultaneously. The proposed methodology demonstrates the potential to reduce FE variability by up to 34% over six driving patterns of different traffic conditions and driving styles. © 2013 IEEE.
Hazra S.,TVS Motor Company |
Sensarma P.,Indian Institute of Technology Kanpur
IET Renewable Power Generation | Year: 2011
This study presents a detailed investigation on self-excitation of a squirrel-cage induction generator (SCIG) used in a wind energy conversion system. Air-gap flux of the SCIG is gradually built up through controlled current injection from a voltage source converter (VSC), connected directly across its stator terminals. Dc voltage of the VSC is ramped from a small initial value, which is the rectified output of the small terminal voltage developed because of remanent magnetism. Increase in air-gap flux increases generator terminal voltage and output power which further increases the dc bus voltage. The field-oriented control method is appropriately applied both for control of voltage build-up as well as dynamic transients. The critical factors deciding this collaborative excitation are analysed and sufficient conditions are derived analytically. System modelling and analytical results are validated through numerical simulation and verified on a 2.2kW laboratory prototype. © 2011 The Institution of Engineering and Technology.
Hazra S.,TVS Motor Company |
Sensarma P.S.,Indian Institute of Technology Kanpur
IET Renewable Power Generation | Year: 2010
This study presents a rugged and cost-effective scheme for start-up and operation of a stand-alone squirrel cage induction machine (SCIG) for a wind energy conversion system (WECS). A voltage source converter (VSC) directly interfaces the SCIG with an equivalent dc load network, which could also be the DC link of an inverter. The VSC dc bus is supported by an electrolytic capacitor and the proposed scheme ensures reliable start up with these rudimentary components. The dc bus voltage is ramped to the rated value from a small initial voltage produced by remanent magnetism of the SCIG core. Subsequently, the load is applied. The V/f control paradigm for motoring operation is suitably extended to the SCIG for controlling both voltage build-up and dynamic transients. A controller is specifically designed to maintain constant dc bus voltage under wind speed and electrical load variations. Steady-state machine flux is maintained constant up to the base speed, which maximises machine utilisation and power extraction especially at higher wind speeds. The overall system modelling and analytical control design is presented. The proposed control strategy has been validated through simulation and experimentally verified on a low power (2.2 kW) laboratory prototype. © 2010 © The Institution of Engineering and Technology.
Krishna A.S.,Indian Institute of Technology Madras |
Mallikarjuna J.M.,Indian Institute of Technology Madras |
Kumar D.,TVS Motor Company
Applied Energy | Year: 2016
This paper deals with the in-cylinder flow field analysis in a two-stroke engine under motoring conditions by particle image velocimetry (PIV) and computational fluid dynamics (CFD). The main objective is to analyze the effect of engine parameters viz., engine speed, compression ratio (CR) and port orientation on the in-cylinder flows in a loop-scavenged two-stroke gasoline direct injection (GDI) engine, with an aim to help researchers to design fuel efficient and less polluting two-stroke engines. In this study, a single-cylinder 70 cm3 two-stroke engine which is very commonly used for the two-wheeler application, is considered. The engine cylinder is modified to provide optical access into the in-cylinder region. The PIV experiments are conducted at various engine speeds viz., 500, 1000 and 1500 rev/min, and the plane averaged velocity vector fields obtained, are analyzed to understand the in-cylinder flow behavior. The CFD study is also carried out using the commercial CFD code, STARCD, to study and compare the in-cylinder flow parameters at various engine operating conditions. The CFD results are compared with the experimental results to the extent possible. The CFD predictions are found to be in good agreement with the experimental results. Therefore, the CFD analysis has been extended further to understand the effect of various engine parameters on the in-cylinder flows. We found that the turbulent kinetic energy and tumble ratio increased by about 25% and 20% respectively, when the engine speed was increased from 1000 to 1500 rev/min. Also, we found that the turbulent kinetic energy and tumble ratio decreased by about 13% and 26% when the compression ratio was increased from 7 to 8. In addition, we found that the port orientation, rather than port areas had a greater influence on the in-cylinder flow parameters. © 2016 Elsevier Ltd.
Khare S.,TVS Motor Company |
Singh O.P.,TVS Motor Company |
Bapanna Dora K.,TVS Motor Company |
Sasun C.,TVS Motor Company
Engineering Failure Analysis | Year: 2012
The customers of the vehicles reported high noise and vibration in the engine at an early stage of service lifetime. An analysis of the various components of the internal combustion engine was carried out. Subsurface cracks and pit marks were seen in the crank pin, roller bearings and big end surfaces of the connecting rod. It was found that high wear at the interface of these components was the main culprit. A laboratory test set-up was developed to correlate and reproduce the field failures. The loads and boundary conditions obtained from the experiments were used in the finite element model of the connecting rod assembly. Results shows high interfacial pressure and stresses near the junction of web and flange of the connecting rod. The modified design of the connecting rod shows significant reduction in the extreme pressure in FEM resulting in the significant enhancement of durability life in laboratory test. A discussion of the spalling problem has been provided leading to the connection of pick pressure and spalling phenomena. © 2011 Elsevier Ltd.
Vaishya A.L.,TVS Motor Company |
Phadnis S.,TVS Motor Company
SAE Technical Papers | Year: 2013
In the recent past, the non-geared (step less) transmission scooters are becoming more popular mainly due to ease of driving without gear shift hassle. Typically these scooters transmit the power through a continuously variable transmission commonly called as CVT. The CVT of a scooter is generally air cooled and located in a protective chamber. This chamber reduces the heat transfers between the CVT and the atmosphere. The temperature reached inside the chamber during the operation of the CVT is quite high, especially when the CVT is operated in hot environment. This may reduce the service life of the drive-belt since it generally decreases when the average operating temperature increases. Along with V belt, high temperature inside CVT chamber also deteriorates durability of centrifugal clutch liner, bush, centrifugal rollers and other CVT parts. Therefore, it is necessary to limit the operating temperature of the CVT system. The main objective of this research is to investigate temperature of CVT parts and optimize the air flow path and air flow rate inside CVT chamber. Tests were carried out to measure the surface temperature distribution of CVT parts and air temperature distribution inside CVT chamber under different vehicle test conditions. This study has contributed to measure the temperature and identify the main causes affecting CVT cooling. Results with improved CVT chamber cooling were also plotted. © Copyright @2013 SAE Japan and Copyright @ 2013 SAE International.
Subbiah S.,TVS Motor Company |
Singh O.P.,TVS Motor Company |
Mohan S.K.,TVS Motor Company |
Jeyaraj A.P.,TVS Motor Company
Engineering Failure Analysis | Year: 2011
Automotive industries perform durability tests on vehicles in the end-user environment to reduce failures and warranty costs in the end-user hands. In this paper we present the failure analysis of muffler mounting brackets of three-wheeler vehicles observed during the durability test. Cracks at the weld location between the engine cradle and brackets were observed in all the vehicles at an average distance of 10,000. km. Many possible causes of the failures are identified using fishbone diagram. The fishbone diagram is a graphical analysis tool that provides a systematic way of looking at effects and the causes that contribute to those effects. Statistical analysis of the failure data was conducted using Weibull distribution for durability life prediction. Further investigations were carried out on the design using finite element method (FEM). A FEM model was developed for the engine cradle assembly in which engine and muffler were modeled as point mass. Vertical forces were applied on the assembly using '4. g' criterion, where g is the acceleration due to gravity. The applied force accounts for the high impact forces that act on the structure during durability testing. Results show high magnitude of stresses and strain energy at the weld location. Analysis of the design suggests that bracket was acting as a cantilever beam with one-plane welding mounted on the engine cradle. Modified design, though eliminated the above failure, shifted the failure mode to the bush-bracket region. Various design modifications were carried out and its effect on durability has been discussed. FEM analysis on the final design shows significant reduction in stresses at the critical locations. The new design of the bush-bracket system passed the durability target of 1,00,000. km. © 2011 Elsevier Ltd.
Kavekar P.C.,TVS Motor Company |
Ghodeswar D.B.,TVS Motor Company
SAE Technical Papers | Year: 2013
In order to comply with the existing emission norms of BSIII in India or EURO III and beyond that also, it is not sufficient to use the catalytic converter technology alone over the wide range of engine operating maps. Different studies across the world have proved that the cost, drivability, operating range against AFR, heat dissipation rate characteristics of catalytic converter limit their use in startup and idling conditions. One common way to tackle this condition is to use the Secondary Air Injection (SAI) system. In this system, small amount of air is injected after the exhaust port to initiate the thermal oxidation of gases. The right amount of air injected at the right time and at right location will reduce the emission by 37-90%. In the following study, SI engine vehicle with single cylinder, 160 cc and having carburetor is used as a test vehicle to evaluate the performance of SAI. The SAI system is modeled in AVL BOOST software and validated against the experimental data. The experimental data is collected at transient condition of IDC (Indian Driving Cycle). SAI system of the same vehicle is modified for different parameters like reed stopper height, SAI outlet pipe length and angle of secondary air injection. In order to avoid the complexity in experiments, DOE technique is used. The optimum parameters of SAI are determined for maximum CO conversion efficiency with uncoated CAT. The combination giving best conversion efficiency is then tested with coated CAT for emission cycle. Model results and the experimental results are compared on the basis of mass flow rate. © Copyright @2013 SAE Japan and Copyright @ 2013 SAE International.
Singh O.P.,TVS Motor Company |
Sreenivasulu T.,TVS Motor Company |
Kannan M.,TVS Motor Company
Applied Acoustics | Year: 2014
Fins as extended surfaces are attached to the internal combustion engine surfaces for enhancing the heat transfer. However, these fins vibrate at various frequencies, which produce undesirable radiated noise. To mitigate this effect, automobile industry inserts rubber dampers between these fins. These rubber dampers reduce the fins' amplitude of vibration and thus reduce the radiated noise from the fin surfaces. Investigations on the effect of rubber dampers on the engine's NVH (Noise-Vibration-Harshness) and thermal performance using numerical (FEM and CFD) and experimental measurement have been presented in this paper. Experiments were conducted in the semi-anechoic chamber on an engine with and without rubber dampers to measure the radiated noise from the fins. It was found that rubber dampers assist in reducing engine high frequency noise signals at higher engine speeds. Modal and harmonic response analysis was carried out on various designs for NVH characteristics improvement. Prototypes of the final design was made and tested for the NVH performance. Computational fluid dynamics (CFD) simulations were performed on engine with and without rubber dampers to investigate the thermal performance. It was found that rubber dampers increase engine temperature by about 10%. Effect of rubbers dampers on the cost and environmental impact has also been discussed. This paper provides a systematic procedure to investigate the effect of rubber dampers and a method to eliminate these dampers from the engines with the same NVH and better thermal performances. © 2013 Elsevier Ltd. All rights reserved.
Kumar S.,Indian Institute of Technology Roorkee |
Durga Shankar Gupta,TVS Motor Company |
Singh I.,Indian Institute of Technology Roorkee |
Sharma A.,Indian Institute of Technology Roorkee
Journal of Reinforced Plastics and Composites | Year: 2010
This study investigates the ballistic response of laminated composite plates using numerical simulations. Numerical simulations were carried out to determine the ballistic response of thick Kevlar/epoxy composite plates, commonly used in body armor. These plates were impacted at velocities between 100 and 1000 m/s. The numerical parametric study of ballistic impact caused by cylindrical projectile is undertaken to obtain an estimate for the ballistic limit velocity, energy absorbed by the plate, and the contact duration. The effect of mass and diameter of the projectile on ballistic limit velocity was also studied. The results obtained hereby are in good agreement with the experimental data presented by other researchers. © 2010 The Author(s).