Preliminary results from a study to model the interaction aerodynamics and aeroacoustics of the main-and tail rotor of a helicopter in subsonic flow are presented The configurations studied are: 1) two-bladed main-and tail rotors in hover, and 2) a four-bladed main rotor and two-bladed tail rotor in climbing flight. The unsteady pressure on the main-and tail rotor surfaces is computed with an unsteady 3-D panel method with full-Span free wake simulation of the simultaneously rotating rotors. The computed pressures serve as input to a Ffowcs williams Hawkings-equation based acoustic code to evaluate the noise characteristics.
展开▼
