The Pointwise mesh generation software has been integrated with NASA’s PEGASUS overset grid assembly software and has the capability to redistribute structured grid points to improve overset grid interpolation accuracy. In the proposed effort, Pointwise mesh redistribution capabilities will be enhanced to support solution-based mesh adaptation.
Specifically, the target size field will be extended to support anisotropic metrics, such as those generated by shocks in the flow field, to improve computational efficiency. Mesh redistribution efficiency and robustness will be improved when adapting grid blocks with strong stretching in one or two directions as is often the case for near-body grids generated using hyperbolic marching algorithms. Finally, to meet NASA’s application needs, the redistribution methods will be parallelized to operate efficiently with large (200+ million cell) grid systems.
The proposed mesh adaptation technology will improve the accuracy of overset grid simulation by controlling solution error at a fixed computational cost. Furthermore, by simultaneously adapting to the solution and to overset assembly information, the entire overset grid system can be optimized for solution efficiency and accuracy. Such improvements will enable NASA modeling and simulation personnel to more efficiently complete mission objectives such as air vehicle performance validation.
NASA has developed extensive overset simulation tools with application in air vehicles (both fixed and rotating wing), space vehicle launch, assent, and entry, parachute deployment, and complex moving-body problems. The proposed technology will work seamlessly with all of these applications.
Military applications include vehicle aerodynamics and store separation. Civil applications include vehicle aerodynamics, propulsion integration, rotorcraft, medical device, power generation, and complex moving-body problems. There is essentially no market limitation for the overset method.