Combined Viscous Vortex Particle Method with a Near Body CFD Solver for Rotorcraft Comprehensive Analysis

The unsteady rotor wake is a complicated flow problem and remains a challenging aspect of comprehensive rotorcraft analysis. The Phase I research has shown that a viscous vortex particle method (VVPM) can provide a first-principle-based solution to the challenging rotor wake problem. Applying VVPM for wake vorticity transportation, while using a modern near body CFD solver for resolving vorticity sources of the rotor blades or fuselage will render an effective hybrid aerodynamic solution in support of comprehensive rotorcraft analysis. This Phase II SBIR will fully develop and implement the coupled VVPM/CFD/CSD solution for an accurate prediction of the rotor wake vorticity variation and the rotor airloads calculation. The proposed SBIR research emphasizes the fundamental rotorcraft wake dynamics modeling and resulting airloads prediction accuracy. The development will address the integration of the state-of-the-art VVPM with a modern rotorcraft comprehensive analysis program, such as RCAS, in support of rotorcraft research, design, and engineering applications. The Phase II work will also emphasize the modularization of VVPM to make it sufficiently versatile that it can be used as a plug-in module for general solver integration platforms, such as HI-ARMS.