The Numerical Study Of The Occurrence And Development Of Coherent Structure In The Boundary Layer Of Turbulent Flow

In this paper, the three-dimensional, time dependent, incompressible Navier-Stokes equations were numerically solved by the compact finite difference and Fourier spectral hybrid method. The stimulation of a turbulent flow was studied using this method in order to further understand the mechanism for the occurrence and development of coherent structure. For this numerical method third order mixed explicit-implicit scheme was employed for the time discretization, and the space discretization was implemented using the Fourier spectral expansion and high order compact finite differences. The basic flow is Spalding profile and the initial value of a single coherent structure in the boundary layer was obtained on the basis of the idea of resonant triad in the theory of hydrodynamic stability, using both T-S model and Gauss model.The results showed that: T-S wave model corresponding to symmetry streamwise vortex while Gauss model corresponding to asymmetry streamwise vortex, and in Gauss model, coherent structure will develops faster and easier.