Maximum Thrust Studies of an Isolated Rotor with CFD Turbulence Modelling and Grid Sensitivities

Abstract

The prediction of the aerodynamic performance of the helicopter rotor at its operational boundaries is a challenging task. This study investigates the effect of various common numerical settings of computational fluid dynamic solvers onto the maximum thrust prediction of a hovering rotor. Thus, this study is distinguishing itself from other research as it leaves the usually analyzed regime around the maximum Figure of Merit. First, the impact of the time steps is investigated, coupled and followed by the spatial accuracy, the type of computational grid and lastly the impact of different turbulence models and their variations. It is observed that for moderate thrust around the maximum Figure of Merit of the rotor, the impact is little with respect to the difference at maximum thrust. The outcome is that the more recent adaptions of turbulence models should be applied in combination with a well resolved spatial resolution with a matching time step.