BOUNDARY LAYER INDUCED NOISE IN AIRCRAFT, PART I: THE FLAT PLATE MODEL

Abstract The importance of boundary layer contributions to aircraft cabin noise levels implies a need for a simple model capable of providing sufficient physical insight to address the problem at the design stage. This paper described the initial form of such a model, which is based on the sound radiated by a single, flat, elastic plate under boundary layer excitation. A numerical study of the model is presented, the main conclusions of which are that, for bare cabin walls, increasing the structural damping and decreasing the skin stiffness and number of reinforcements will reduce the radiated sound. High excitation levels, due to matching between the boundary layer and elastic wave velocities, are difficult to avoid, but the effect is not overly sensitive to small variations in cruising speed of structural parameters.