Computational Investigation of a Full-Scale Proprotor Hover Performance and Flow Transition

Abstract

The full-scale XV-15 proprotor hover performance and flow transition phenomena are numerically investigated using an unsteady Reynolds-averaged Navier–Stokes flow solver. The rotor figure of merit is predicted over a range of blade collective angles, and computed skin frictions on the rotor surface are compared with the wind-tunnel experimental data. A grid resolution study is performed to investigate the impact of the mesh resolution on hover predictions using a baseline mesh and a refined mesh. The Langtry–Menter local correlation-based transition model is used to predict the skin friction and transition onset associated with the XV-15 rotor under the framework of both the Spalart–Allmaras one-equation turbulence model and Menter’s shear-stress transport two-equation model. Computational results show satisfactory predictions for the XV-15 hover performance and transition phenomena and offer an improved understanding of complicated rotor flow physics for the XV-15 proprotor.