Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : June 29, 2016 - July 01, 2016
It is well known that the diffraction and the interference are characteristic properties of waves as commonly observed in various physical phenomena. Additionally, the recent optical engineering has made advances in the application of acousto-optical effect, which is characterized by the diffraction and the deflection of light waves through the interaction with acoustic waves. Being inspired by the effect, the present investigation deals with an acoustic-acoustic wave interaction where the diffraction and deflection of a sound wave occur when it passes transversely across the strong acoustic standing wave, namely the ‘virtual slit’, generated by coaxially placed loudspeakers. First, an approximate numerical model is developed based on phased line array source theory which simulates the interaction of outgoing sound wave through apertures into free space. Based on the numerical prediction, the wave deflection by both the physically existing slit and the virtual slits is then explored experimentally by measuring sound field over the slits. Both numerical and experimental investigations show that the incoming sound waves into the tilted slits can be deflected in the direction approximately as intended. Leaving some issues to be solved for the practical use, the suggested wave deflection control method can be used as one of the noise abatement technologies.
