SOUND-PROPAGATION IN A WIND-TUNNEL - COMPARISON OF EXPERIMENTS WITH FFP AND RESIDUE SOLUTION

Several models and solutions have been developed for propagation in th e presence of refraction and ground of finite impedance. These include the fast field program (FFP) and the residue solution. In this paper, the results obtained with these theories are compared with scale mode l sound propagation experiments performed in a wind tunnel. The data a re obtained in the presence of relatively steep wind speed profiles wh ich have stable gradients and provide a good test for the theories. In addition, a single procedure to approximate realistic profiles by an equivalent linear profile is discussed.