1 Use of Active Surface Waviness for Control of Cavity Acoustics in Subsonic Flows

This work is concerned with the application of a simple passive control device with the main focus a comparative analysis of the unsteady cavity flow present during landing phases of flight. Potential application for the current study as a method cavity oscillation is derived from the idea of either increased shear layer thickening or disruption of the feedback mechanism from cavity leading edge application of modification and a passive method of control. A full two-Dimensional investigation of testing of cavity control mechanism, with sensitivity analysis of varying surface frequency and amplitude were carried out. The results of the study found accurate modeling of cavity flow characteristics with discrete acoustic frequencies being observed. Furthermore significant attenuation of Sound Pressure Levels existing in the cavities was achieved. This considered being a highly significant result, which offers encouragement to such mode of control. Nomenclature D = cavity depth L = cavity length h = step heigh