Unstructured Overset Grid Adaptation for Rotorcraft Aerodynamic Interactions

A new adaptation strategy is presented that permits time-dependent anisotropic adaptation for dynamic overset simulations. The current development permits adaptation to be executed over a periodic time window in a dynamic flow field so that an accurate evolution of the unsteady wake may be obtained within a single unstructured methodology. Unlike prior adaptive schemes, this approach permits grid adaptation to occur seamlessly across any number of grids that are overset, excluding only the boundary layer to avoid surface manipulations. Demonstrations on rotor-fuselage interactions, including flow field physics, time-averaged and instantaneous fuselage pressures, and wake trajectories are included. The ability of the methodology to improve these predictions without user intervention is confirmed, including simulations that confirm physics that have before now, not been captured by computational simulations. The adapted solutions exhibit dependency based on the choice of the flow field featurebased metric and the number of adaptation cycles, indicating that there is no single best practice for feature-based adaptation across the spectrum of rotorcraft applications.