Improved Prediction of Complex Rotorcraft Aerodynamics

Turbulence and transition modeling still accounts for most of the uncertainties in numerical modeling of complex flows associated with rotorcraft vehicles and components. Computational fluid dynamics (CFD) methods typically cannot capture complex physics with traditional Reynolds-averaged Navier-Stokes (RANS)-based models since majority of physics are transient and occur at different scales. Over the past decade, a resurgence in research related to turbulence modeling has resulted in new large eddy simulation (LES)-based turbulence techniques that have improved computations that involve separated flows. The accuracy of a hybrid RANS-LES technique, first shown to improve turbulent predictions on rotors in the DARPA Quiet Helicopter program, have been increased via locally varying coefficients