用非交错网格求解曲线坐标系下的流动控制方程

本文采用非交错网格法,求解任意曲线坐标系下的流动控制方程。文中阐述了压力振荡的根本原因和相应的消除措施,导出了压力修正方程中控制体边界上曲线速度分量的修正表达式。在这些表达式中,出现了一个表征一个网格间距和两个网格间距压力梯度差分值的附加差值项。当出现压力振荡时,该差值很大,可以有效地消除振荡,而当压力场没有振荡时,这一差值又很小。作为计算方法可靠性的检验,本文分别计算了二维直通道和渐缩形混合管内的气流流动问题,结果是令人满意的。

A Numerical Study for Governing-Equations of Flow in Curvilinear Coordinate Systems with Nonstaggered Grids

The nonstaggered grids are adapted in this paper for solving the governing e-quations of flows in the curvilinear coordinate systems. The present paper domonstrates the basic reason and corresponding eliminating method for the pressure oscillation,and deduces the corrected expressions for the curvilinear velocity components. in which an additional term respresenting the difference between the 1- Sx and 2- Sx difference schemes for the pressure gradient appears. Thus if an oscillatory pressure field were to arise,the magnitude of this term would be large and would act to remove the oscillation;where as for the required non-oscillatory field the magnitude of this term remains small. As examination for the numerical methods, 2-D turbulent flow in straight duct and 2-D mixing flow in gradually convergent duct are calculated respectively. The numerical results are satisfactory.