近壁湍流相干结构的数值模拟

NUMERICAL SIMULATION OF COHERENT STRUCTURE IN THE WALL REGION OF TURBULENT FLOW

提出了近壁湍流对称单个相干结构的理论模型，采用紧致有限差分和Ｆｏｕｒｉｅｒ谱展开相结合的数值方法研究它的演化问题，得到雷诺应力分布及高剪切层的形成过程与实验结果一致。

In the paper, the three dimensional,time dependent,incompressible Navier Stokes equations are numerically solved by the compact finite difference and Fourier spectral hybrid method. A third order mixed explicit implicit fractional step scheme is here employed for the time discretization.The space discretization is implemented using the Fourier spectral expansion and high order compact finite differences. A theoretical model of the symmetric single coherent structure in the wall region of turbulent flow is proposed,utilizing the idea of resonant triad in the theory of hydrodynamic stability. The evolution of the model is numerically studied by the numerical method. The obtained Reynolds stress distribution and the process of the formed strong shear layer are in reasonable agreement with experimental results.