The Design Optimization of Truck Cabin to Reduce Interior Noise by Virtual and Experimental Testing

Abstract

Human hearing ability is in the range of 20 Hz to 20000 Hz. Noise that exceed the allowable value as established by Occupational Safety and Health Administration (OSHA) which is 90 dB(A) can be considered as hazardous sound. If exposed for long period, it will cause negative effects such as discomfort and permanent loss in hearing ability. Noise, Vibration and Harshness (NVH) is a study that revolves around comfort issues of occupants, particularly in vehicles. newlineThe research from past shows that the noise level for driver cabin and rear cabin do not exceed the allowable noise limit, which is 90 dB (A). Much research has not been done in automobile interior design in comparison to fine art or other commercial or industrial arts. However, automobile design affects the journey of millions of passengers to greater degree, ergonomically, economically and culturally, than many other subjects. newlineSeveral sources are responsible for the noise in truck cabins. Most are located front of, or underneath the cabin. Engine noise is generally 9 to 10 dB (A) higher in diesel powered trucks than in those by gasoline. newlineSound level, changes with measuring location, especially when the windows are open. Since, the driver is the person in the cabin most of the time, it would be more desirable to place the measuring microphone at the height of drivers head location position, so that one can assess the noise to which he is effectively exposed for hearing conservation purposes. newlineWhen dealing with speed as a factor involved in changes in noise level, the following three situations have been considered. newlinei) Engine started and vehicle stationary. newlineii) Engine started with Full Acceleration and vehicle stationary. newlineiii) Vehicle moving at 30 km/h. speed newlineiv) Vehicle moving at 50 km/h. speed. newline newline newlineThe TATA ace vehicle having 702 cc is chosen for this work. Analysis and testing of cabin noise level is an emerging research area. Limited work is recorded in the NVH analysis of mini truck cabins compared to heavy goods vehicle cabins.