Method for Calculating Flow Fields around Moving Bodies

摘要

A new method for calculating flow fields with arbitrarily moving boundaries is proposed. Under the concept of Lie derivative, field equation moving coordinates are derived. There are several kinds of such equations; an exmaple is one written in Viviand's conservative form. According to the formulation presented, it is natural and reasonable to consider that the computation coordinates fitted to the body move in space. This is the reverse of the usual computational procedures. The two dimensional incompressible Navier-Stokes equations in general moving coordinates are solved by a finite difference method. Using the third-order upwind scheme (Kawamura scheme), the present calculations are made for the dynamic stall process on an oscillating airfoil, and the flow generated by a moving cylinder. Consequently it is shown that the flow generated by a moving body can easily be analyzed by the present method.