Steady Simulation of an Isolated Helicopter Rotor in Hover Configuration with the DLR TAU-Code

Abstract

In the present CFD study a simulation of a helicopter rotor in hover configuration is performed with the DLR Tau-Code. Computations are performed on a multi-block structured Chimera mesh for the blade pitch angles -6°, -4°, -2°, 0°, 2°, 4°, 5° with an angular velocity of 36.35 [1/s] and a Reynolds number of 4.15 Mio. The results obtained are compared with results obtained in previous investigations preformed with the DLR FLOWer solver. Furthermore calculations on a hybrid one-block mesh using periodic boundaries are performed. All computations are computed with the one-equation turbulence model SAE and with the two-equation turbulence model Wilcox k-omega. The thrust and power coefficients obtained with the DLR TAU-Code present a good agreement with the FLOWer results using the same grid and the same turbulence model. Anyhow discrepancies on the rotor performance are observed among the results obtained with the different turbulence models applied. The results obtained with the hybrid one-block mesh show considerable deviations on the rotor efficiency principally due to mesh topology and wake resolution of the grid, which effect is also analyzed in the present study.