Improved Prediction of Complex Rotorcraft Aerodynamics

摘要

Turbulence and transition modeling still accounts for most of the uncertainties in numerical modeling of complex flowsrnassociated with rotorcraft vehicles and components. Computational fluid dynamics (CFD) methods typically cannotrncapture complex physics with traditional Reynolds-averaged Navier-Stokes (RANS)-based models since majority ofrnphysics are transient and occur at different scales. Over the past decade, a resurgence in research related to turbulencernmodeling has resulted in new large eddy simulation (LES)-based turbulence techniques that have improved computationsrnthat involve separated flows. The accuracy of a hybrid RANS-LES technique, first shown to improve turbulentrnpredictions on rotors in the DARPA Quiet Helicopter program, have been increased via locally varying coefficients.