Helicopter Fuselage Drag Prediction: State of the art in Europe

Abstract

This paper presents the final results obtained during the computational task of the Brite-Euram HELIFUSE programme. The calculations were conducted by three National Research Centers (CIRA, DLR and ONERA), three Helicopter Manufacturers (Agusta, Eurocopter and GKN-Westland), one Software Company (SIMULOG) and two University Laboratories (DTU and IAG). The test cases considered concern two simplified geometries of the DGV fuselage which had been tested in the course of the project, aiming to analyze Reynolds number and geometry effects on the fuselage flowfield and loads. The results show the progress completed in Reynolds Averaged Navier-Stokes simulations during this cooperation. They prove that RANS methods can accurately compute the flowfield and the loads around a fuselage provided that sufficiently fine grids are used. Low speed preconditioning techniques which have been applied by some of the partners are necessary for improving the accuracy on pressure drag at low Mach number conditions. For the configurations considered where limited separation occurs the turbulence model has a very weak influence on the solution. Finally it is shown that current RANS methods can accurately reproduce strut interference effects which appear in the wind tunnel tests.