Tata Technologies (Singapore)

The automobile is a complex integration of electronics and mechanical components. One of the major components is the differential which is limited due to its shortcomings. The paper proposes a concept of a cost effective differential lock and traction for passenger cars to sports utility vehicles alike, employing a parallel braking mechanism coming into action based on the relative speeds of the wheels driven by the differential. The paper highlights the employment of minimum number of components unlike the already existing systems. The system was designed numerically for the traction control and differential lock for the world’s cheapest car. The paper manages to come up with all the system parameters and component costing making it a cost effective system.

<div class="section abstract"><div class="htmlview paragraph">Liquid ring pumps are used in aircraft fuel systems in conjunction with main impeller pumps. These pumps are used for priming the pump system as well as to remove fuel vapor and air from the fuel. Prediction of cavitation in liquid ring pumps is important as cavitation degrades the performance of these pumps and leads to their failure. As test based assessment of cavitation risk in liquid ring pump is expensive and time consuming, recent approaches have been to assess and predict the risk of cavitation using Computational Fluid Dynamics (CFD) methods with the goal to quicken the design process and optimize the performance of these pumps.</div><div class="htmlview paragraph">The present study deals with the development and assessment of a CFD methodology to simulate cavitation for a liquid fuel pump used in aircraft fuel systems. The study simulates the cavitation phenomena using a multi-phase flow model consisting of fuel vapor, air, and liquid fuel phases. The rotation of the blades is simulated using two approaches, a steady state multiple reference frame approach and a transient sliding mesh approach. The results demonstrate that the numerical model employing transient sliding mesh approach along with a standard k-e turbulence model, although computationally expensive, is required to predict the cavitation phenomenon in liquid ring pumps accurately.</div></div>

<div class="htmlview paragraph">Recent advances in automotive noise control engineering have reduced the general level of noise in the passenger car compartment and focused more attention on irritating noises. Buzz, Squeak and Rattle (BSR) have surfaced as major concerns. Customers increasingly perceive squeak and rattle as direct indicator of vehicle build quality and durability as revealed from the J. D. Power surveys. The high profile nature of squeak and rattle has motivated the manufacturers to pay attention during early phase of vehicle development program. Traditional methods of prevention and elimination of squeak and rattle have been found to be no longer sufficient to develop acceptable products in shortened product development cycle. Basic causes, design guidelines and validation technique using laboratory simulation and digital data acquisition have been successfully developed to push the BSR prevention process upstream in the development cycle.</div> <div class="htmlview paragraph">A test procedure to map the vehicle BSR performance with the use of laboratory simulation and digital data acquisition tools has been developed. The vehicle BSR performance is evaluated based on the subjective rating system. As commitment towards customer to meet his expectations in quality right from purchase till the useful life of vehicle, the vehicle BSR performance is monitored till the end of life. Lab simulation technique allow determination of sub-system or prototype vehicle degradation much early in the development process. Simulation is used to map the progression of noise with respect to vehicle life and usage conditions. Targeting at reducing noises after durability exposure, effectively later in the vehicle life, is crucial in ensuring new vehicle quality.</div>

In recent days, rapid machining through digital prototyping has been popular for its applicability in a wide range of complex and useful parts. Rapid construction of prototypes from point cloud data based on section plane method is available, which is an approximate method. Discusses some suitable methodology for conversion of point cloud data to a physical prototype where data acquisition is through a mechanical touch trigger probing process using CNC milling machine. The process is quite useful for reverse engineering of complex sculptured parts. A concept called tangent plane method is adopted for the generation of 3D geometry on point cloud data of sculptured parts with due emphasis on probe radius compensation after data capture and tool radius compensation during tool‐path generation. Computer simulated results are presented, based on real‐world point cloud data.