Automated Generation of Viscous CFD Grids for Increased Productivity of High Fidelity Aerodynamic Analysis

Viscous analysis is vital for a complete understanding of missle and UAV aerodynamic properties. This proposal offers a technique for generating grids suitable for viscous analysis on complex configurations.The principle idea is to divide the region closest to the body into a sequance of inter-connected zones and generate body-conforming grids in these zones.The body-conforming grids are restricted to a prescribed normal distance from the body.The near-surface grids, partitioned into a number of patches, allow the automatic generation of the grids with aspect ratios suitable for viscous flows. In the outer region, where convection dominates, unstructured cartesian or cartesian-like meshes can begenerated quickly and easily. A transitional grid is used as a bridge between regions. The entire grid can be treated as one single-zoned unstructured grid with an unstructured solver or as a hybrid grid with multiple zones and multiple solvers. In thehybrid approach, viscous solvers are used for the near-body zone while the faster inviscid solvers can be used in the farfield. In Phase I a proof-of- concept grid generator will be demonstrated using candidate missle geometries. In the Option period,intial solver development will begin and be continued in Phase II. The software developed will be used for viscous calculations of shapes of interest to the US Army and defense contractors. The generation of grids can be automated completely facilitatingfast turn-around.