Plate-angle effects on acoustic waves from supersonic jets impinging on inclined plates

The effects of plate angle on acoustic waves from a supersonic jet impinging on an inclined flat plate at angles of 30, 45, and 60 deg are numerically investigated. Three-dimensional compressible Navier-Stokes equations are solved using the modified weighted compact nonlinear scheme. Similar to previous studies, the acoustic fields indicate that there are at least three types of acoustic waves in all of the cases considered herein: 1) Mach waves generated from the shear layer of the main jet, 2) acoustic waves generated from the impingement region, and 3) Mach waves generated from the shear layer of the supersonic flow downstreamof the jet impingement. Acoustic waves (2) are generated from two different acoustic sources: 1) the interaction between the plate shock wave and the shear layer, and 2) the interaction between the bubble-induced shock waves and the shear layer. The frequency characteristics of acoustic waves are related to the thickness of the shear layer in the impingement region. The results of the present study indicate the source location and the characteristics of acoustic waves (2) for various flat-plate angles. © Copyright 2015 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.