Wake-Capturing Methods for General and Heavy-Lift Rotorcraft Flow Analysis

The proposed VC Module will directly address a critical shortcoming of current CFD techniques for modeling the rotor wake, the excessive numerical dissipation of vorticity. A pressing and immediate application will be the evaluation of fuselage and empennage loads on rotorcraft under development. The ability of the VC module to accurately represent the rotor wake for a large amount of time would enable designers to anticipate and correct configuration issues such as tail buffet and main-rotor tail-rotor interference associated with the impingement of the main rotor wake on the empennage of the aircraft. Historically, the inability to address these issues through analysis early in development has led to costly redesigns of military and civilian rotorcraft involving repeated flight tests and reconfiguration late in the design life of aircraft. The proposed software module offers a significant and important potential to completely eliminate the added costs and delays associated with these issues that have always plagued rotorcraft development projects. The relevance of this issue is echoed by the endorsement letter provided from Boeing Helicopters with this proposal.