DNS of a plane mixing layer for the investigation of sound generation mechanisms

• DOI: 10.1016/j.compfluid.2007.02.002
• Publication Date: 2007-02-21T07:16:34Z
• Authors: Andreas Babucke; Markus Kloker; Ulrich Rist
• Keywords: Inflow; Compressible flow

Direct numerical simulations in two and three dimensions have been performed to investigate the sound generation by vortex pairing in a compressible plane mixing layer with Ma1 = 0.5 being the upper and Ma2 = 0.25 being the lower stream Mach number. The Reynolds number based on the vorticity thickness at the inflow and the velocity of the upper stream is Re = 500. The flow is forced at the inflow with eigenfunctions obtained from viscous linear stability theory including threedimensional disturbances. The results are verified with linear stability theory and the two-dimensional simulations performed by Colonius, Lele and Moin [6]. The excitation of a steady longitudinal vortex mode leads to an early three-dimensional deformation of the travelling spanwise vortices and reduced sound emission to the slower fluid stream side.