Validation of the Strand Grid Approach

Abstract

We explore a new approach for automated mesh generation for viscous flows around geometrically complex bodies. A prismatic-like grid using “strands” is grown a short distance from the body surface to capture the viscous boundary layer, and adaptive Cartesian grids are used throughout the rest of the domain. The advantages of this approach are many; nearly automatic grid generation from triangular or quadrilateral surface tessellations, very low memory overhead, and automatic mesh adaptivity for time-dependent problems, and fast and efficient solvers from structured data in both the strand and Cartesian grids. Solvers on the two grid systems are coupled using a Chimera overset approach so the scheme is readily applicable to problems with moving bodies. The paper focuses on validation of the approach for fundamental flow problems, fixed-wing, and rotary-wing applications. Comparison to experiment and to other well-established codes are provided. Results show the approach shows considerable promise, with load computations from the automatically generated strand meshes comparable in accuracy to manually generated fully unstructured meshes, and with excellent resolution of vortex wakes.