3D Euler Methods for Multibladed Rotors in Hover and Forward Flight.

Kurzfassung

The flowfield of a hovering rotor is calculated solving the Euler equations formulated in terms of the absolute flow variables in a blade attached coordinate system. Results for two hover cases with multibladed rotors have been presented, which show a good agreement between calculation and experiment. Due to the implementation of a multi-grid technique the computing times for hover calculations could be reduced considerably. The change of the discretization scheme form a cell centered to a cell vertex scheme shows advantages in the accuracy of the results, if the same computational grids were used. On the other hand a further convergence acceleration can be obtained, because coarser grids can be used without losses of accuracy. A time-accurate 3D Euler method for rotors in forward flight has been developed. Results for two non-lifting and three lifting forward flight cases have been presented. The agreement between.