Calculation of Multibladed Rotors in Forward Flight Using a 3D Navier-Stokes Method

This paper presents numerical simulations based on the solution of the Euler and the Reynolds averaged Navier-Stokes equations of the flow around the 4-bladed 7A and 7AD rotors in forward flight. The chimera technique is applied in order to allow for the relative motion of the blades which are assumed to be rigid. The numerical results are compared with the experimental data of the S1 Modane wind tunnel in form of pressure distributions, normal force coefficients and total thrust. Details concerning the computational effort for the simulations are given. The numerical results agree qualitatively well with the experimental data but the quantitative agreement is only fair. It is concluded that a trim of the CFD simulations including aero-elastic effects is necessary to considerably improve the predictions.