Investigation of the Fluid-Structure Interaction and the Radiated Sound of Different Plate Structures Depending on Various Inflows

Experimental and numerical investigations of the fluid-structure interaction as well as the sound, induced by the turbulent flow over different plate structures and radiated to the acoustic far field, are presented. To modify the standard inflow condition that is a fully turbulent boundary layer, two obstacles are placed upstream of the observed plate. In order to investigate the influence of such a plate on the wall-near flow field, the flowinduced vibration of the plate structure is measured using a laser-scanning vibrometer. Furthermore unsteady pressure measurements are performed at the plate surface. Based on these vibration measurements, the radiation of vibrational sound to the acoustic field is computed employing a finite-element (FE) acoustics solver. The sound transmission into a plenum chamber mounted at the back side of the plate is calculated by use of a Statistical Energy Analysis (SEA) model based on the results of the unsteady pressure measurements. Microphone measurements are carried out to generate a basis of comparison. The experiments are performed in an acoustic wind tunnel. The results allow for the separation of vibrational and flow-induced sound radiated to certain positions in the field surrounding the plate.