抄録
To measure sound absorption coefficient under parallel flow is studied through experiment and numerical analysis of three dimensional sound field. The dimensions of the measuring space are 600mm high, 600mm long and 50mm wide. Both boundaries of the space are connected to duct silencers to pass air flow. The boundaries of this measuring space must be non-reflecting to apply two microphones technique for measuring sound absorption coefficient. The sound fields with these boundaries are computed to evaluate the degree of non-reflecting for some numerical models to compare the experimental data. After ascertaining the validity of this measuring space, the effect to sound absorption coefficient of perforated panel with air space under parallel flow is measured.
