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Technical Paper

Radiated Noise Reduction in a Single Cylinder Direct Injection (DI) Naturally Aspirated (NA) Engine

Small goods carrier and passenger vehicles powered by Naturally Aspirated (NA) Direct Injection (DI) diesel engines are popular in Indian automobile market. However, they suffer from inherently high radiated noise and poorly perceived sound quality. This paper documents the steps taken to reduce the radiated noise level from such an engine through structural modifications of major noise radiating components identified in the sound power analysis. The work is summarized as follows; Baseline radiated noise measurements of power train and identification of major noise sources through sound intensity mapping and noise source ranking (NSR) in an Engine Noise Test Cell (ENTC) Design modifications for identified major sources in engine structure Vehicle level assessment of the radiated noise in a Vehicle Semi-Anechoic Chamber (VSAC) for all the design modifications. A reduction of 7 dB at hot idle and 4 - 8 dB in loaded speed sweep conditions was observed with the recommended modifications.
Technical Paper

Optimization of an Air Intake System to Reduce Multiple Whoosh Noises from an Engine

The direct injection common rail technology coupled with variable geometry turbocharger on the modern diesel engine has improved the diesel engine performance (power and torque) greatly as compared to the conventional diesel engine. Diesel engine performance is greatly dependent on the abundant air availability. And it is facilitated by Variable Geometry Turbocharger (VGT) in modern engines. The engines with variable geometry turbocharger offer quick response to the demand in various driving conditions especially in transient driving conditions. During transient driving conditions, the air intake system experiences a rapid air flow pressure and velocity changes. The pressure differentials across air intake system during transient events allow flow direction changes in the system. This kind of phenomenon generates unusual “Multiple Whoosh” noises in the air intake system of the sport utility vehicle engine.
Technical Paper

Investigation of Frequent Pinion Seal and Hub Seal Leakages on Heavy Commercial Vehicles

The automotive sector is going through a phase of stiff competition among various Original Equipment Manufacturers for increasing their profitability while ensuring highest levels of customer satisfaction. The biggest challenge for such companies lies in minimizing their overall cost involving investments in Research and Development, manufacturing, after sales service and warranty costs. Higher warranty costs not only affect the net profit but in turn it also affects the brand image of the company to a large extent in the long run. An effort is made here to target such warranty costs due to frequent tail pinion and hub seal leakages on single reduction/hub reduction axles of Heavy Commercial Vehicles in the field. A preliminary study involving the severity analysis of such failures is followed by a step by step investigation of these failures.
Technical Paper

Thermal Management in Engine Compartment for Efficient Working of the Intercooler on a Rear Engine Vehicle

This paper is related to a vehicle with rear engine which is turbo charged and inter cooled. Due to packaging constraints the intercooler was placed in front of turbocharger and was exposed to hot air radiated out from the turbo charger. This was in turn reducing the efficiency of the intercooler. In such scenario, it is essential to shield the turbo charger from the intercooler for proper hot air management. Also rear engine vehicles don't have the benefit of ram air affect. This necessitates increasing the air entering in to the core of the intercooler. Both the above mentioned issues associated with such a vehicle was resolved by ensuring that the hot air from turbo-charge is guided away from the intercooler as well as the air flow to Intercooler is increased. Guiding or throwing out the hot air away from Intercooler was done by introducing a heat shield or a baffle between the two.
Technical Paper

Micro Hybrid Battery Management - A Novel System to Augment Engine Restart Reliability and Battery Life

The micro hybrid system, also known as the engine stop start system, has recently gained prominence world over due to its considerable fuel saving potential and relatively low costs. In spite of being a relatively non-complex function, the stop start system works hand-in-hand with a wide range of vehicle systems and components, specially the starting system and the battery. Frequent idle stop periods during city driving conditions can result in excessive battery discharge and gradually lead to loss of engine restartability. Increased number of charging and discharging cycles tend to reduce the life of the battery significantly. Hence it is very essential that the micro hybrid vehicles have a system in place that monitors and maintains the battery status within its operating limits.
Technical Paper

Effect of Carbon Black Fraction in Natural Rubber for Automobile Rubber Components

Large number of studies have been carried out and references are available on the use of synthetic rubber with non-carbon black fillers. Use of carbon black reinforced natural rubber is very common in automotive applications especially suspension top cups, cab mounts, suspension bushes, engine mounts etc Carbon black plays key role in the alteration of the rubber compound properties to suit the end product requirements for hysteresis, stiffness, hardness, compression set etc. This paper gives experimental details, results, and conclusions on and effect of carbon black in natural rubber compound. Carbon black reinforced natural rubber formulations were made and keeping all other ingredients of the formulation constant including type of carbon black and by varying only the amount of carbon black dosage. Since the rubber components call for different specifications based on the end product requirements, it is not possible to have common rubber formulation for all the end products.
Technical Paper

Tangentially Mounted Inserts: A Good Avenue for Recycle

Recycle, Reuse, Repair have become a mantra today for cost reduction. More importantly it reduces the demand of natural resources and helps protect environment. There are many ways in which cutting tools can be recycled. Some examples are used up extra long drill [1] and used up crankshaft grinding wheel [2]. Used up indexable inserts can also be reused by grinding a groove to remove the blunt/dull portion [3], selecting an application where the unused portion of a large cutting edge can be put to reuse [4], reuse by grinding a corner radius to remove the blunt/dull portion [5]. This article explains the concept of reuse of used up tangentially mounted plain inserts and shows that such mounting is best suited for the recycling of indexable inserts and can substantially reduce the tool cost. This recycle can reduce the consumption by almost 50% or more depending on the nature of dullness of insert during the initial use. Conserving natural resources is therefore a good possibility.
Technical Paper

Methodology for Measurement of Inherent Driveline Frictional Force for a Vehicle in Coasting Mode

Today, with the introduction of Euro-III engines it is possible to achieve almost zero fuel consumption in coasting mode. This means more the distance covered in coasting mode better will be the overall fuel economy of the vehicle. In turn, distance covered by the vehicle in coasting mode depends on the driveline frictional losses i.e. for a particular moving inertia of a vehicle higher the inherent driveline frictional loss lesser will be the distance negotiated by the vehicle. The proposed methodology has been established to determine this inherent frictional force component acting all across the driveline while the vehicle is run in coasting mode under no-load condition. The application of this methodology is limited to vehicles with manual transmission.
Technical Paper

Simulation of Intake System for Two Cylinder Naturally Aspirated In-Direct Injection Engine

This paper summarizes the approach towards the process of computational simulation of the intake system and its experimental investigation. It is an important aspect to improve breathing of the diesel engines for performance, torque smoothening and emissions. This can be achieved by optimizing intake system parameters such as plenum volume, diameters, length of ports & runners, etc., which directly correlates the volumetric efficiency, thereby the performance of the engine. Keeping the objective of improving volumetric efficiency to achieve low-end performance, the intake system design optimization has been done on a twin cylinder, four cycle, compression ignition, In-Direct Injection (IDI) engine. For the simpler intake system, the primary pipe length & diameter can be calculated by mathematical formula applying Helmholtz Resonator principle. But, for a complex intake system, simulation software is used here.
Technical Paper

Effect of Fuel Injection Parameters and EGR on Exhaust Emission of a 3 L Diesel Engine

Simultaneous reduction of NOx and PM from engine exhaust of a diesel engine is an interesting area of research due to the implementation of stringent emission regulations all over the world. Cost involved in expensive after treatment systems such as DPF and SCR necessitate minimization of engine out pollutants. With minimum engine out emission achieved through engine hardware and combustion parameter optimization, possibility of elimination or downsizing of the after treatment system can be explored. The paper presents the effect of fuel injection parameters and EGR rate on exhaust emission of a boosted diesel engine. Effects of parameters such as rail pressure, pilot-post injections, SOI, EGR rate and EGR temperature on a 4 cylinder two valve direct injection diesel engine is studied. Present study reveals the possibility of elimination of after treatment systems at BS IV level with optimization of engine hardware and combustion parameters.
Technical Paper

How to Enhance Gear Shift Feel of North-South Transmission Layout

Globalization has intensively driven focus of car manufacturers on comfort and ergonomics. Luxuries are becoming essential features of product mix. Customer’s expectations and desires are changing because of cut throat competition and increasing variety of options. In order to sustain in marketplace, OEM has to be competitive while providing features and options with appropriate quality. Vigorously changing dimensions and definitions of comfort level, luxury and aesthetics has driven the intense focus of OEM’s on customer touch points, customer touch points are those components of vehicle which customer accesses while driving the vehicle and they play vital role in generating drive feel of vehicle. Customer’s drive feel about the vehicle is most complex and critical factor and is of subjective nature. Now days drive feel is an important aspect of product differentiation. Gear shift feel is very crucial touch point in overall drive feel of vehicle.
Technical Paper

Improving Fuel Economy of Commercial Vehicle by Introducing Optimized Electro-Magnetically Coupled Fan Drive

Increasing fuel cost and constant pressure to maximize the fuel economy are forcing OEMs in India to look for alternate engine cooling mechanism which will minimize the power take off from the engine without affecting the system reliability. Aim of this paper is to analyze the potential benefit of incorporating Electro-magnetic fan (EMF) drive in terms of fuel economy and reduced load on the engine. These benefits were compared with the conventional viscous coupled fan drive system. In vehicle with viscous coupling, fan RPM is based on the ram air temperature at coupling face which takes heat from turbo-charged air and coolant. On the other hand, EMF drive have a separate controller and control the fan RPM based on the coolant temperature enabling itself to respond directly to changes in the heat load as compared to viscous coupling having indirect representation of Coolant/charged air temperature.
Technical Paper

Development of an optimized cooling system for a light duty Pickup truck

With the advent of most advanced diesel engines the demand for upgraded engine cooling modules capable of handling more heat rejection in a smaller space is surging. Moreover, the variance in the operating conditions, i.e., the simultaneous cooling demands for peak load as well as partial load in different ambient conditions of the vehicle operation, broadens the scope of development of a cooling system. Also, the cooling system needs to be configured judiciously so as to cater effective cooling at peak loads and efficient cooling at partial loads. This research paper deals with a cooling system developed using modularity approach in order to have a control over tuning of subsystems for varying operating conditions and also to achieve the performance targets with a compact design adhering to packaging constraints. Kuli simulation of different designed configurations were carried out for identification of best concept.
Technical Paper

Optimization of Multiple Injection Strategies to Improve BSFC Performance of a Common Rail Direct Injection Diesel Engine

Present stringent emissions norms; global fossil fuel energy scenario and competitive automotive market has driven many researches on diesel engine combustion in both academic and industry level. This work is an effort to improve the fuel economy without compromising emissions level of typical six cylinders inline CRDI diesel engine using optimized multiple injection strategy. There was some unusual nature of BSFC (Brake specific fuel consumption) observed on such typical engine. Also, Torque curve was not up to the mark for better drivability. This engine is equipped with most familiar in cylinder NOx reduction device namely EGR and multiple injections. There were few experiments conducted on same engine to optimize the BSFC using different multi injection strategies in line to marginal change of injection timing with respect to crank angle. Total exercise was done following partial Design of Experiments (DOE). EGR % has kept unaltered.
Technical Paper

Cost Effective Techniques to Maximize Benefits of Entry Segment Full Hybrid Electric Vehicle without Engine Downsizing

Hybridization with engine downsizing is a regular trend to achieve fuel economy benefits. However this leads to a development of new downsized engine which is very costly and time consuming process, also engine downsizing demands for expensive higher power electric system to meet performance targets. Various techniques like gear ratio optimization, reducing number of gears, battery size and control functionalities optimization have been evaluated for maximum fuel economy keeping system cost very low and improving vehicle performance. With optimized gear ratios and reduced number of gears for parallel hybrid, it is possible to operate the engine in the best efficiency zones without downsizing. Motor is selected based on power to weight ratio, gradient requirements, improved acceleration performance and top speed requirement of vehicle in EV mode.
Technical Paper

Prediction and Resolution of Vehicle In-Cab Noise due to Powertrain Induced Excitations

Vehicle NVH is one of the critical performance quality parameter and it consists of vibration levels at tactile points and noise levels at ear locations for different vehicle running conditions. There are many sources of noise and vibration in a vehicle, and powertrain is one of the main source. Therefore, it is important to understand and resolve powertrain induced noise and vibration issues at early design stage with efficient simulation techniques. The work presented here deals with the use of systematic CAE approach for prediction and resolution of structure borne in-cab noise due to powertrain excitations. During NVH testing of SUV vehicle, boom noise is observed at low frequency. Detailed full vehicle level simulation model consisting of vibro-acoustic trimmed BIW, front and rear suspension, and driveline with powertrain modal model is built.
Technical Paper

Thermal Mapping of HPAS System Based on Steering Kinematic and Tire-Road Contact Patch Sliding Model

In hydraulic power assisted steering (HPAS) system higher steering oil temperature can cause deterioration of oil reservoir, thermal failure of pump/valves and can diminish system performance. Thermal analysis is performed for HPAS system architecture development in order to maintain steering oil temperature within design limits for optimal performance & increased life of HPAS steering system. In present study mathematical model of HPAS system consisting of steering pump, flow and pressure control mechanism, rotary valve, steering circuit pipes and hoses, thermal interaction with ambient is developed. The model is able to predict steering torque-hydraulic pressure dynamics of HPAS system as per design. Developed HPAS system model is integrated with steering kinematic and uniquely developed tire-road contact patch sliding model for estimating non-linear rack force behavior at higher steering angle.
Technical Paper

Derivation of Test Schedule for Jerk Test on Manual Gearbox Using Road Load Data

Shock loads/Jerk is a major cause of gearbox failure which occurs during abusive driving condition. In passenger car torque spikes are experienced by the transmission during launch/sudden clutch release events on flat road or off-road. Whereas, in case of commercial vehicle torque spikes are generated while operation in mines and off-road application especially in tipper vehicles. Torque spikes experienced by the gearbox can lead to gear failure, gear slippage and structural failure of housing. Research has been done till now to improve the design of gearbox to address such failures. However, with increased focus on transmission downsizing and improved vehicle performance (by weight reduction and more powerful engine) it is necessary to have optimum design to meet transmission life. This paper discuss the test setup and methodology used to simulate the torque spikes on test bench. To develop the test procedure huge data was collected on commercial vehicles.
Technical Paper

Reduction in Human Effort in Shifting and Selection Forces in Manual Transmission system

Transmission system is important part of automobile. In the current era of automobile, there are two types of gear shifting mechanism: manual and automatic. Manual gear shifting mechanism is complex and require much effort for shifting and selection of gear so to surmount much effort by kinematic analysis of linkages, joints ergonomically. By changing these parameters in gear shifting mechanism it gives flexibility and less effort for shifting and selection of gear. It also reduce feasibility of error of shifting and selection of gear. Transmission system is modeled in CREO 2.0 and measuring and data analysis of the shift and selection forces of gear was done with the load sensor shown in Figure 6 and programming was done in LABVIEW 2015. The final cause of this technical paper is to decrease physical effort by driver for shifting and selection of gear.
Technical Paper

Development of Dc Motor based E-Shift Mechanism for Manual Transmission

Transmission designs over the years have evolved significantly achieving more efficiency in terms of fuel economy, comfort and reduction in emissions. This paper describes a Dc motor based E-shift mechanism which automates an existing manual transmission and clutch system to give comfort and ease for gear shifting. The basic idea of E-shift mechanism is to make hassle free gear shifting of manual transmission at sole command of driver without any control strategy for automatic shifting as in case of Automated Manual transmission (AMT). The E-shift mechanism will eliminate the manual efforts required for pressing clutch pedal and shifting gear, giving more ease while driving. The developed mechanism can be retro fitted on existing manual transmission without any major modification at lower cost. The E-shift mechanism uses two actuators for gear shifting and one actuator for clutch actuation.