Study on Noise Reduction of High-Powered Suction Truck (Consideration of phase difference between two pressure fluctuations of SHAC silencers)

Kunihiko Ishihara, Tomoya Hamada, Toshinobu Iwamoto

A main noise source of the high powered suction truck is a pressure fluctuation of a blower and the noise is radiated from the final component named “4th catcher”. Two holes are provided at the upper and the lower parts of the blower as a means to get cool the blower and two SHACs (Self Help Air Conditioner) are connected to the blower by two hoses. The present study aims to clarify the achievement of the noise reduction to use the phase difference which can be made by two different lengths of hoses. As a result, the use of fluctuating pressure data before connection of two ports doesn’t go well in the prediction of the noise reduction but go well by use of the data after the connection and the phase difference is the most important factor in the prediction of the noise reduction in using the idea of the interference type silencer.