Science China Physics, Mechanics & Astronomy

, Volume 57, Issue 5, pp 963–970

Experimental evidence for non-linear growth in compressible mixing layer

Authors

  • TieJin Wang
    • State Key Laboratory for Turbulence and Complex Systems, College of EngineeringPeking University
    • China Academy of Aerospace Aerodynamics
    • State Key Laboratory for Turbulence and Complex Systems, College of EngineeringPeking University
  • XiaoTian Shi
    • State Key Laboratory for Turbulence and Complex Systems, College of EngineeringPeking University
    • China Academy of Aerospace Aerodynamics
  • Ning Hu
    • State Key Laboratory for Turbulence and Complex Systems, College of EngineeringPeking University
    • China Academy of Aerospace Aerodynamics
  • ZhenSu She
    • State Key Laboratory for Turbulence and Complex Systems, College of EngineeringPeking University
Article

DOI: 10.1007/s11433-014-5432-2

Cite this article as:
Wang, T., Chen, J., Shi, X. et al. Sci. China Phys. Mech. Astron. (2014) 57: 963. doi:10.1007/s11433-014-5432-2

Abstract

An experimental study of compressible mixing layers (CMLs) was conducted using planar laser Mie scattering (PLMS) visualizations from condensed ethanol droplets in the flow. Large ensembles of digital images were collected for two flow conditions at convective Mach numbers Mc = 0.11 and 0.47. The coherent vortices, braids and eruptions in the mixing zone were observed, interpreted as evidence of multi-scale, three-dimensional structures at a high Reynolds number. The mixing layers with a large visualized range present two stages along the streamwise direction, corresponding to the initial mixing and the well-developed stage. A new method, the gray level ensemble average method (GLEAM), by virtue of the similarity of the mixing layer, was applied to measure the growth rate of the CML thickness. New evidence for a nonlinear growth of CML is reported, providing an interpretation of previous observations of the scattering of the growth rate.

Keywords

compressible mixing layergrowth ratecoherent structuresflow visualization

Copyright information

© Science China Press and Springer-Verlag Berlin Heidelberg 2014