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Sound Quality (SQ) of brake and clutch pedal assembly plays an important role in contributing to vehicle interior noise and perception of sound. Quiet operation of brake and clutch units also reflects the vehicle built and material quality. Noise emitted from these sub-assemblies has to meet certain acceptance criteria as per different OEM requirements. Not much work has been carried on this over the years to characterize and quantify the same. An attempt has been made in this paper to study the sound quality of brake and clutch pedal assemblies at component level and validate the same by identifying the parameters affecting SQ. Effect on noise at different environmental conditions was studied with typical operating cycles in a hemi-anechoic chamber. The effect of sensor switches integrated within the clutch and brake pedal on sound quality is analyzed. It is found that the operating characteristics of switches drives the noise and SQ.

In order to reduce development time and costs, application of numerical prediction techniques has become common practice in the automotive industry. Among the wide range of simulation applications, prediction of the vehicle interior noise is still one of the most challenging ones. The Finite Element Method (FEM) is well known for acoustic predictions in the low-frequency range. As part of the development of a full sized bus model, noise levels at Driver Ear Levels (DEL) and Passenger Ear Levels (PEL) were targeted. The structural and acoustic analysis were performed for a bus to reduce interior noise in the low-frequency range. Various counter measures were identified and structural optimization/modifications were performed from virtual simulation to reduce the DEL and PEL. Structure-borne noise due to both road-induced vibration and engine vibration were considered by using FEM techniques.

Greater customer awareness is driving the automotive industry to constantly look to innovate and ensure that greater time, efforts and considerable resources are spent in developing a better vehicle. As we move away from noisy vehicles, the differentiating parameter in vehicles is the perception of quality in the vehicle noise or sound. As the masking effect due to overall vehicle noise level abates, many low noise sources gain prominence, which directly influences the perception of noise refinement. Hence, the concept of vehicle interior noise is not only limited to lower noise levels but has also extended to better sound quality (SQ). SQ technique involves use of relevant parameters for quantifying a subjective quality into an objective quantity. This paper will look at parameters relevant to subjective perception of vehicle interior noise and consider a benchmarking methodology targeting vehicle sound quality.

Gerotor pump is a positive displacement pump unit which is widely used for lubrication in on-road and off-road engine applications. This paper is focused on Gerotor pump design competency established at ARAI comprising of design of inner and outer rotors, suction & delivery ports, optimizing inlet and outlet diameters & its position, development of methodology to calculate oil flow rate, volumetric efficiency, mechanical efficiency & slippage. The finalization of design is followed by CFD of Gerotor pump to optimize the pressure and flow pulsation. A trochoidal profile is used to design the inner and outer rotors and its conjugate profile are realized by a set of equations using a method based on the theory of gearing. Suction and delivery port is analytically designed based on the same design parameters of the trochoidal profile.

An open wheeled open cockpit high speed car with 800 CC MPFI engine was developed validated and run at 105 kmph. The key focus was to build a car with superior aerodynamic characteristics especially in terms of drag. This work discusses in detail about the design and simulation of car using CFD package followed by Wind Tunnel testing. The design of high speed car starts with design of seat according to the ergonomics of the driver followed by the space frame. Based on the space frame designed, the body panels are sketched and CAD model is developed. The CAD model is imported in CFD package for virtual testing and validated through wind tunnel results. For this 1:3 scale model was manufactured using Rapid Prototyping.

With emission norms getting more and more stringent, the trend is shifting towards electric and hybrid vehicles. Electric motor replaces engine as the prime mover in these vehicles. Though these vehicles are quieter compared to their engine counterpart, they exhibit certain annoying sound quality perception. There is no standard methodology to predict the noise levels of these motors. Electric motor noise comprises of mainly three sources viz., Aerodynamic, Electromagnetic and Mechanical. A methodology has been developed to predict two major noise sources of electric motor out of the three above viz. Mechanical and Aerodynamic noise. These two noise sources are responsible for the tonal noise in an electric motor. Aerodynamic noise arises most often around the fan, or in the vicinity of the machine that behaves like a fan. This noise is predominant at higher motor speed and also in electric vehicle due to higher speed fluctuation.

Virtual modeling of engine and predicting the performance and emissions is now becoming an essential step in engine development for off-road application due to the flexibility in tuning of the combustion parameters and requirement of shorter development times. This paper presents an approach where the test bed calibration time is reduced using virtual techniques, such as 1D thermodynamic simulation and 3D CFD combustion simulation for 4 cylinders TCIC engine complying with Stage IIIA emission norms. 1D thermodynamic simulation has played an important role in the early stage development of an engine for selection of engine sub systems like turbocharger, manifolds, EGR system, valve timings etc. The application of 1D Simulation tool for combustion system development, focusing on NOx emissions for an off road multicylinder mechanical injection diesel engine is discussed.

This paper presents a methodology for predicting thermal comfort inside Midibus cabin with an objective to modify the Heating, Ventilation and Air Conditioning (HVAC) duct design and parametric optimization in order to have improved thermal comfort of occupant. For this purpose the bus cavity is extracted from baseline CAD model including fully seated manikins with various seating positions. Solar Load has been considered in the computational model and passenger heat load is considered as per BSR/ASHRAE 55-1992R standard. CFD simulation predicted the air temperature and velocity distribution inside passenger cabin of the baseline model. The experimental measurements have been carried out as per the guidelines set in APTA-BT-RP-003-07 standard. The results obtained from CFD and Experimental test were analysed as per EVS EN ISO7730 standard and calculated occupant comfort in terms of thermal comfort parameters like Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD).

In high speed race cars, aerodynamics is an important aspect for determining performance and stability of vehicle. It is mainly influenced by front and rear wings. Active aerodynamics consist of any type of movable wing element that change their position based on operating conditions of the vehicle to have better performance and handling. In this work, front and rear wings are designed for race car prototype of race car. The high down force aerofoil profiles have been used for design of front and rear wing. The first aerodynamic analysis has been performed on baseline model without wings using CFD tool. For investigation, parameters considered are angle of attack in the range of 0-18° for front as well as rear wing at different test speeds of 60, 80, 100 and 120 kmph. The simulation is carried out by using ANSYS Fluent. The simulation results show significant improvement in vehicle performance and handling parameters.