Research on Unsteady Aerodynamic Interference for the Tiltrotor Aircraft in Hover

Abstract

The high resolution numerical simulation for rotor/wing-body interaction flow-field in hover is crucial for the accurate prediction of aerodynamic performance of the tilt-rotor aircraft, and is the one of the important issues of helicopter aerodynamics. Based on the moving-embedded grid technique, a CFD simulation method for predicting unsteady flow-field is established. Reynolds-averaged Navier-Stokes(RANS) equations are used as governing equations and Spalart-Allmaras turbulence model is employed, implicit LU-SGS scheme is adopted. On this basis, the unsteady interaction flow-field of the rotor/wing-body are investigated in deep research, and the special phenomenon“fountain effect” is obtained. The different preset flaps/ailerons affect on decreasing rotor/wing-body aerodynamic interference is studied. The results show that the total thrust is lossed about 16.6%, the aerodynamic interference is lowest when the preset flaps/ailerons angle is 45°, and the total thrust loss is reduced to 13.8% from 16.6%.

Keywords

• tilt-rotor aircraft
• moving-nested grid
• navier-stokes equations
• unsteady numerical simulation
• aerodynamic interference