槽道湍流相干结构的研究

采用高阶差分方法求解非定常不可压Navier-Stokes方程，进行槽道流相干结构的数值研究，与常用的谱方法相比，不需限制边界条件，可用于更一般的粘性流体的流动问题，文中所用时间分裂法和三维耦合高阶差分格式适用于包括邻近边界点在内的整个计算区域，克服了三维各自用高阶中心差分格式不适用邻近边界点的困难。通过算例模拟了槽道流动中单个相干结构的演化发展规律，结果与实验一致。

Investigation on Turbulence Coherent Structure in Channel Flow

The three dimensional time dependent incompressible Navier Stokes equations are numerically solved with finite difference method,and the evolution of single coherent structure in the channel flow is numerically studied. As compared with the frequently used spectral method, this method does not require the restriction boundary conditions,and is able to use with more ordinary flow questions on viscous fluid. This paper adopts the fractional step method and the three dimensional combined higher order central difference scheme applied to the entire calculative region, and overcomes the difficulty that three dimensional separated higher order central difference scheme is not adapt able to points near boundary. The evolution of the single turbulence coherent structure in channel flow is numerically simulated, and significant results are in correspondence with experiments.