The acoustic wave from a shock-vortex interaction: comparison between theory and computation

Experimental, theoretical, and computational research has shown that the interaction of a shock with a vortex produces a quadrupolar acoustic wave. Although the theoretical basis for this has been accepted for some time, there has not been a detailed comparison of the predictions for the pressure variation around and through the acoustic wave to the pressure fields obtained from numerical simulations. In this paper, Ribner's theory is used to predict the acoustic pressure field evolving from a shock interacting with either a Rankine (or infinite) vortex or with a composite (or finite) vortex. A comparison of these theoretical results indicates the importance of vortex geometry on the acoustic wave. Then the theoretical results are compared to the results of detailed computations. The computational results were obtained by solving the two-dimensional conservation equations for mass, momentum, and energy for a compressible, inviscid fluid using the Flux-Corrected Transport algorithm. These results show that there is good qualitative agreement between the theory and the computation. (C) 2000 The Japan Society of Fluid Mechanics and Elsevier Science B.V. All rights reserved.