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The acoustical performance of a vehicle dash panel system is rated by the noise reduction, which is calculated from the sound transmission and absorption characteristics. A typical dash insulator consists of a steel panel (vehicle body panel), a porous decoupler and heavy layer in the form of sandwich construction. The use of dash panel is to block engine noise from entering into the interior cabin. In the present study the transmission loss of dash panel has been evaluated in reverberation chambers and the sound absorption of dash panel has been determined in impedance tube. This paper deals with improving over all sound transmission loss and shifting of the double wall resonance well below the engine firing frequencies by changing the decoupler materials such as felt and foams of different density and thickness and heavy layer mass per unit area.

Recent trends towards design of High Performance Diesel engines creating more challenges in the area of design, durability and NVH aspects of components and systems. In particular, Valvetrain system of High Speed application engines is one of the most critical and complicated dynamic system in terms of precise control of events, max. Lift, control over accelerations and vibration related issues. This can be tackled by designing the cam profile for better valve train dynamics. High frequency components and/or excessive jerks in a cam profile are important sources of cam-follower vibrations. There are various techniques of designing cam profile to achieve controlled valve train dynamic behavior at high speed operations. Present paper discuss the impact of various cam profile options designed using Polydyne, N-Harmonic and B-Spline methodologies on a field problem of cam wear for high speed engine application.

The present numerical study investigates the design and analysis of a concept model Le Mans Grand Touring Prototype (LMGTP) car. Through analysis, aerodynamic pitch sensitivity and related factors are found to be detrimental to the straight-line stability of these high-speed race cars. Simulations are carried out on a commercial Computational Fluid Dynamics (CFD) tool for varying pitch angles of the car from −1° to +2.5°. For each pitch angle, steady-state pressure contours, velocity contours, and streamlines are presented. Additionally, coefficients and force values of lift and drag are calculated with the k-omega turbulence model implemented. Obtained numerical results are validated via Ahmed Body studies reported in the literature, and an average error deviation of 1.013% is exhibited. It is observed that lift force at the front axle increases with increasing pitch angles, leading to reduced pitch stability.

Three dimensional finite element analysis of mufflers has been carried out using ANSYS general purpose program. Analysis of simple expansion chamber muffler, extended tube muffler, tapered chamber muffler, offset chamber muffler and flow reversing chamber muffler has been carried out to predict the transmission loss. This three dimensional FEA technique has proved to be successful for the analysis of geometrically complicated mufflers where one dimensional theories can not be used. Parametric analysis of a simple expansion chamber muffler has been carried out to study the effect of expansion ratio, expansion chamber length, number of partitions within a chamber and unequal partitions. Analysis of acoustic cavity of a simple expansion chamber muffler has also been carried out to predict the natural frequencies and acoustic mode shapes.

The major challenge that is faced by most of the engine manufacturers nowadays is to meet the stringent emission norms with least modification in the engine design. In achieving the emission norms simplicity of the design has to be maintained as far as possible by optimizing the available emission control techniques. This paper deals with such optimal technique with reduced cost and up gradation of the engine from CPCB I to CPCB II in minimum time with minimum design changes. This difficult task is achieved by adopting direct continuous EGR and intercooler with appropriate injection timing and optimizing the fuel injection pump in a cost effective manner. The experiment is carried out on 2.86 litre turbocharged engine giving power output 44.5 kW @1500 rpm. In order to achieve the NOx emission norms LLR FIP is used, to retard the injection timing at part loads to reduce the in-cylinder temperature.

A test engineer faces a series of considerations (decisions) when designing a test program to conduct service history simulation testing of full scale vehicles (structures) in the laboratory. This paper proposes a logical decision path, with pertinent discussion of tradeoffs, which is intended to serve as a design guide in this process. A good deal of the authors’ subjective opinion is included. The paper begins by presenting a model of how a test facility should interface to the total engineering process. This is important in establishing a proper division of responsibility for the validity and usefulness of test results. This is followed by a specific discussion of service history simulation testing for durability evaluation.

The purpose of this paper is to present the past and present concepts of mechanical test optimization, which means the adjustment of a test machine command signal to achieve desired amplitude and mean levels. In particular, the methods of null pacing, dynamic frequency control, classical amplitude control, and maximum velocity limiting / control are discussed along with their respective application areas, advantages and disadvantages. Also, the factors of data verification and over-complication of the test are noted.

The ground mobile robotics study is structured on the two pivotal members namely Sensor Perception and Motion Planning. Sensor perception or Exteroception comprises the ability of measurement of the layout of the environment relative to vehicle's frame of reference which is a necessity for the implementation of safe navigation towards the goal destination in an unstructured environment. Environment scanning has played a significant role in mobile robots application to investigate the unexplored environment in the sector of defence while transporting and handling material in warehouse and hospitals. Motion Planning is a conjunction of analyzing the sensor's information while being able to plan the route from starting point to the target destination. In this paper, a 3600 2-D LiDAR is used to capture the spatial information of the surrounding, the scanning results are presented in a local map and global map.

Dual fuel operating strategy offers great opportunity to reduce emissions like particulate matter and NOx from compression ignition engine and use of clearer fuels like natural gas. Dual-fuel engines have number of potential advantages like fuel flexibility, lower emissions, higher compression ratio, better efficiency and easy conversion of existing diesel engines without major hardware modifications. In view of energy depletion and environmental pollution, dual-fuel technology has caught attention of researchers. It is an ecological and efficient combustion technology. This paper summarizes a review of recent research on dual-fuel technology and future scope of research. Paper also throws light on present limitations and drawbacks of dual-fuel engines and proposed methods to overcome these drawbacks. A parametric study of different engine-operating variables affecting performance of diesel-CNG dual-fuel engines vis-à-vis base diesel operation is also summarized here.

5 belt wind tunnels are the most common facility to conduct the experimental aerodynamics development for production cars. Among aerodynamic properties, usually drag is the most important development target, but lift force and its front/rear balance is also important for vehicle dynamics. Related to the lift measurement, it is known that the “pad correction”, the correction in the lift measurement values for the undesirable aerodynamic force acting on wheel belt surface around the tire contact patch, must be accounted. Due to the pad correction measurement difficulties, it is common to simply subtract a fixed amount of lift values from measured lift force. However, this method is obviously not perfect as the pad corrections are different for differing vehicle body shapes, aerodynamic configurations, tire sizes and shapes.

The cross flow design of a radiator and its heat transfer and temperature drop was simulated then validated by using a data acquisition system during both static and dynamic running conditions of a Formula SAE car. The data acquisition system simulated and validated the radiator's cross flow design and heat transfer, as well as the temperature drop, under static and dynamic conditions in a car. The optimal radiator design determines the engine's operating temperature and the desired temperature drop gain through proper design of the inner core, number of fins and tubes, and radiator material. The purpose of a properly designed radiator is to prevent the combustion engine from heating up above its operating temperature [1]. The radiator's design is based on the operating temperature of the CBR 600RR engine. The highest temperature recorded was around 105°C, and in the worst case scenario, it can reach 110°C.

In internal combustion engines, rate of fuel burning known as burn rate is a simplified representation of complex in-cylinder combustion process. It is considered as a prime input especially in 1D simulation tool for all important thermodynamic studies. A novel parametric model for prediction of burn rate in heavy duty Direct Injection (DI) diesel engine has been introduced in the present work. A wide range of experimental data with more focus on higher load points with different in-cylinder combustion characteristics is considered and burn rates have been generated using measured pressure trace. Generated burn rates have been studied over different phases of combustion. These burn rate shapes have been analyzed to understand the effect of fuel injection system, air management subsystem parameters along with in-cylinder conditions on combustion. Different mathematical modelling approaches for burn rate approximation like Wiebe function have been studied.

Autonomous driving is looked upon as solution for future of automotive vehicles. The technology has tremendous possibilities to improve safety, fuel economy, comfort, cost of ownership etc. The project to develop an autonomous controller from scratch was undertaken, with objective to drive under selected test scenarios. The car, modified to drive using this autonomous controller, is able to handle these scenarios. The key scenarios include ability to successfully drive on tracks with well-marked lanes, Follow the route as per selected trip plan file, recognize and follow all traffic road signs, traffic signals en-route, identify other vehicles on the road or pedestrians in the lane and take the appropriate action. The development was carried out using frugal engineering approach. As the Autonomous Vehicle technology is still under development, the standard proven published approaches are not available.

An analytical approach to developing motorcycle suspensions is presented. Typical uncontrolled and subjective evaluations that place limits on suspension development are curtailed through the use of a laboratory-based road simulation technique, which evaluates vehicle ride quality. Ride comfort is calculated using a specifically tailored NASA model after primary and secondary frequency regimes have been established for this type of motorcycle. Correlation between road and laboratory simulation is measured and compared to the road data variance. A designed experiment evaluates changes in ride quality as a function of suspension and tire pressure adjustments. Various suspension settings are repeated on the simulator and corresponding ride numbers are calculated for both environments. An analysis is performed to correlate ride quality improvements on the simulator with ride quality improvements in the field.

Measurement of sound intensity techniques has very good application in the source identification of a particular noise character. It has been applied effectively along with modal analysis and FE experimental excitation techniques to find out root cause of a particular noise character in small gasoline engine. A FEM shell model was used to make cylinder block and cylinder head model. FEM simulation was carried out which matched with experimental results. It helped to remove the noise character from engine. The other part of the paper describes the noise reduction of the crankcase cover used for the same motorcycle. It houses crankcase as well as two speed gearbox. The methodology involves very effective combination of experimental harmonic analysis, FE model with the shell element for the 3 piece crankcase cover, and experimental measurements. A particular sequence of this experimental techniques along with computer simulation techniques gives extremely good results.

Gear whine can be reduced through a combination of gear parameter selection and manufacturing process design directed at reducing the effective transmission error. The process of gear selection and profile modification design is greatly facilitated through the use of simulation tools to evaluate the details of the tooth contact analysis through the roll angle, including the effect of gear tooth, gear blank and shaft deflections under load. The simulation of transmission error for a range of gear designs under consideration was shown to provide a 3-5 dB range in transmission error. Use of these tools enables the designer to achieve these lower noise limits. An equally important concern is the dynamic mesh stiffness and transmissibility of force from the mesh to the bearings. Design parameters which affect these issues will determine the sensitivity of a transmission to a given level of transmission error.

The value of crash simulation has long been recognized by carmakers as an essential tool for vehicle development and certification programs. Driven by the need to minimize time-to-market for new models, cost reduction, and by consumer demand for safer cars and trucks, the industry is moving to newer technologies in crash simulation. Crash simulation provides an inexpensive means to quickly simulate the effects of a barrier crash by reproducing its basic elements - acceleration, velocity and displacement - in a nondestructive test. Crash event timing and accuracy of reproduction are critical performance factors. This paper describes the unique features and capabilities offered by a new generation of crash simulators.

Antiroll bar plays an important role in rollover stability of the vehicle. But not only does it limit the vehicle roll during cornering, but also alters the lateral load transfer between the tracks, which in turn affects the cornering performance of the vehicle. This paper deals with the design and mathematical modeling of antiroll bars to reduce the body roll of the vehicle from 1.5°/g to less than 1.0°/g. Rear bar uses a conventional torsion type bar but the front anti roll mechanism is an unconventional antiroll bar using a rotating double cantilever mechanism. Mathematical modeling is done for pushrod rod actuated antiroll mechanisms to simulate its non-linear roll rates. Antiroll bars for front and rear are designed for the calculated stiffness. Finite Element Analysis of antiroll bar and its components is done and the mechanism is tested on the vehicle. Steady state tire model parameters are generated by curve fitting tire testing data into pacejka coefficients.

Turning is a widely used manufacturing process in mechanical machining industries, while the cost associated with this process is high due to the cost involved in changing tools or tool regrinding. All the parameters of turning, like feed rate, cutting speed, and depth of cut, substantially impact the tool wear, which subsequently reduces tool life. Cooling methods like flooding, Minimum Quantity Lubrication (MQL), etc., are incorporated to minimise these effects on the tool and workpiece interface. When using these cooling techniques, the process parameters involved play vital roles in increasing the effectiveness. This paper focuses on the effects of machining parameters on the tool and the workpiece quality. Experiments were conducted to study the impact of various input parameters of the turning process on the tool tip temperature, cutting forces, and tool wear, ultimately affecting the tool's life.

This paper presents the parametric study, process benefits, optimization and chip appearance of machining parameters on turning of the Inconel 718 using Nd: YAG laser source. To analyze the mentioned above effect on alloy 718, the cutting inserts of chemical vapor disposition coated (CVD) TiN/TICN/Al2O3 are used to turn at the time of machining. To evaluate the linear (mean effect plots) and interaction effect (3D surface plots) of laser parameters on the force, roughness and tool wear to keep the minimal, experiments of the L27 orthogonal array are done by selecting the controllable parameters viz speed, the rate of feed along with laser power. From the parametric study, increase in speed and laser power along with decrement in the rate of feed resulted in lower cutting force. But surface finish and tool wear reduced with a decline in speed and scale of feed and increased with increment in laser power.