Numerical investigation in chaos characteristics of macro-mixing efficiency of two-dimensional supersonic mixing layer

摘要

Coherent structures of two-dimensional supersonic turbulent mixing layers with the engineering background have been investigated numerically with large eddy simulation method. The chaos characteristics of transverse sections of mixing layer flowfield have been obtained through the analyses of two chaos characteristic parameters, Lyapunov exponent and correlation dimension. The results show that under the conditions of the present numerical simulations and physical models, the distribution of correlation dimension is roughly consistent with that of streamwise turbulent intensity at transverse sections of mixing layers through analysis of nonlinear time series, as may be used to measure the macro-mixing efficiency of mixing layers quantitatively. The distribution of maximal Lyapunov exponent could be used to validate the quantitative results. Therefore, a potential experimental method measuring the thickness of mixing layers with low costs on the basis of chaos characteristic parameters has been proposed firstly.