Parallel Computing of Overset Grids for Aerodynamaic Problems with Moving Objects

When a store is dropped from a military aircraft at high subsonic, transonic, or supersonic speeds, the aerodynamic forces and moments acting on the store can be sufficient to send the store back into contact with the aircraft. This can cause damage to the aircraft and endanger the life of the crew. Therefore, store separation analysis is used to certify the safety of any proposed drop. This analysis is often based on wind tunnel aerodynamic data or analogy with flight test data from similar configurations. Time accurate computational fluid dynamics CFD offers the option of calculating store separation trajectories from first principles. In the Chimera grid scheme a set of independent, overlapping, structured grids are used to decompose the domain of interest. This allows the use of efficient structured grid flow solvers and associated boundary conditions, and allows for grid motion without stretching or regridding. However, these advantages are gained in exchange for the requirement to establish communication links between the overlapping grids via a process referred to as grid assembly.