A New Method for Computing Laminar-Tubulent Trasition and Turbulence in Compressible Boundary Layers—PSE+DNS

A new method for computing the laminar-turbulent transition and turbulence in compressible boundary layers was proposed.It is especially useful for the computation of laminar-turbulent transition and turbulence starting from small-amplitude disturbances.The laminar stage,up to the beginning of the breakdown in laminar-turbulent transition,was computed by parabolized stability equations(PSE).Then the direct numerical simulations(DNS) method was employed to compute the transition process and turbulent flow,for which the inflow condition was provided by using the disturbances obtained by PSE method up to that stage.In the two test cases,including a subsonic and a supersonic boundary layer,the transition locations and the turbulent flow obtained by this method agree well with those obtained by using only DNS method for the whole process.The merit of using our method is that the computational cost is much smaller than that using only DNS method.