An Optimization Study for Generating Surface-Oriented Coordinates for Arbitrary Bodies in High Re-Flow.

摘要

The numerical coordinate-transformation technique for generating surface-oriented coordinates for arbitrary geometries is examined carefully in order to optimize the procedures involved, especially for high-Reynolds number flow. The areas studied include appropriate stretching of the viscous region while minimizing truncation error and optimum location of the far-field boundary for computational efficiency. Examination of certain limiting forms of the nonlinear partial differential equations for the coordinates is found to lead to useful information about the behavior of the numerical solutions. It also enables the development of a simple procedure for formulating an improved starting solution for the nonlinear equations. Finally, an effort is made to maintain local near-orthogonality for the coordinates in the physical domain. An implicit numerical method of solution, employing these optimization procedures, has led to reduction of the previously required computer time by an order of magnitude, for the cases examined. (Author)