Unsteady Reynolds-Averaged Navier-Stokes-Based Hybrid Methodologies for Rotor-Fuselage Interaction

摘要

LIFTING bodies produce wakes that interact with other bodies immersed in the same fluid. In particular for rotorcraft, the problem becomes significantly more complicated since the rotor wake remains near the vehicle in hover, descent, and low-speed forward flight. The proximity of the wake alters the inflow distribution at the rotor and modifies the helicopter thrust. Moreover, since the main rotor wake may impinge on the fuselage, such interactions are an important consideration in modern rotorcraft design. For example, empennage impingement may result in undesirable handling qualities such as low-speed pitchup and tail buffet. Moreover, the wake can also generate unsteady impulsive loads on the fuselage, resulting in vibrations, thus negatively impacting the crew and passenger flight experience. Given the complexity of rotorcraft interactional aerodynamics problems, it is common for tail and empennage designs to be modified significantly after first flight [1].