Shock-induced noise in 2D sub- and supersonic mixing layers

Abstract

A numerical code solving acoustic analogies to predict shock-induced noise is developed. Both Lighthill's analogy and the one of Ffowcs-Williams and Hawkings (FWH) are implemented and compared to the acoustic far field of the direct numerical simulation (DNS) in detail. In addition to this the linearized Euler Equations (LEE) are used to propagate into the acoustic far field and the results are also compared to the DNS-data. With a two dimensional mixing layer in a subsonic test case and a Reynolds number based on the initial shear layer thickness of , a first application of the code is performed. To investigate the shock-induced noise, a two dimensional supersonic mixing layer with an impinging oblique shock is simulated. The results of the analogies for the shock-induced noise are in good agreement with the acoustic far field of the DNS. The accuracy of the FWH-method is better than the one of Lighthill's analogy.