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

The unsteady rotorcraft wake emanated from rotors, wings, and lifting surfaces is a physically complicated problem and remains a difficult aspect of comprehensive rotorcraft analysis. The recent development of a viscous vortex particle method (VVPM) shows very high promise for providing a first-principle-based solution to the unsteady wake problem. Applying VVPM for wake vorticity transportation, while using a modern near body CFD solver for resolving vorticity sources of the rotor blades, fuselage, and lifting surfaces (such as wing and stabilators), will provide an efficient hybrid rotorcraft aerodynamic solution in support of comprehensive rotorcraft modeling and analysis. This SBIR will develop a formulation of the coupled VVPM/CFD/CSD interface and associated algorithms for numerical simulation. The coupled solution will be demonstrated through test problems for prediction of rotor wake vorticity variation and rotor airloads and response. The proposed SBIR research emphasizes the fundamental rotorcraft wake dynamics modeling and resulting airloads prediction accuracy. The research and development will also emphasize 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.