EVOLUTION AND GROWTH OF LARGE SCALE STRUCTURES IN HIGH COMPRESSIBILITY MIXING LAYERS

Abstract

The basic physical mechanisms for shear layer growth have been shown in computations to change at very high compressibilities. A double diaphragm, shock tunnel driven hypersonic mixing layer facility is used to reach compressibility levels not possible in blowdown-type facilities. Mixing layers at M c  = 0.86 and 1.7 are examined in streamwise, plan, and end views using Schlieren and acetone planar laser-induced fluorescence imaging schemes. Analysis of these images yields normalized shear layer growth rates, concentration information on the fast side of the shear layer, and visualization of the behaviour of large-scale structures along with the associated acoustic radiation. Normalized growth rate data are reported for M c  = 0.80–2.25 as derived from averaged Schlieren images. This article was chosen from selected Proceedings of the Second International Symposium on Turbulence and Shear Flow Phenomena (KTH-Stockholm, 27-29 June 2001) ed E Lindborg, A Johansson, J Eaton, J Humphrey, N Kasagi, M Leschzine...