A Numerical Study For The Generation Of Shocklet By 3-D Disturbance In Supersonic Boundary Layer

Recently, the problem of transition and stability in supersonic boundary layer has attracted more and more attention due to its technical importance. So far, there are few results from the study of the stability problems of compressible flows. Especially for supersonic flows, theoretical investigations are mostly limited to linear problems. Some people have tried to extend the nonlinear theory of incompressible flows to compressible flows. However, shocklets may be found which make the flow field uncontinuous. So it's necessary to know whether have shocklets in flow field.In this paper, the evolution of 3-D disturbances in a supersonic boundary layer of a flat plate was investigated by using DNS. A T-S wave, a couple of T-S waves and three resonant T-S waves were introduced at the entrance separately to study the evolution of the disturbance. Two judgments were employed to detect the shocklets. The results offered certain basis for the establishment of non-linear theory of stability for compressible flows.