Computation of helicopter fuselage aerodynamics using Navier-Stokes CFD methods

This paper describes the research activities conducted by the European Rese arch consortium HELIFUSE during the first year of this Brite-EuRaM project. The work consisted of Navier-Stokes computations on pre-selected test case s taken out of an extensive wind tunnel test program at the ONERA F1 wind t unnel. The calculations were performed by three national research institute s (CIRA, DLR, ONERA), three helicopter manufacturers (Agusta, Eurocopter, G KN-Westland), one software company (Simulog) and two universities (DTU, IAG ). The aim of the work was to simulate the complex flowfield around the fus elage of the wind tunnel tests. Blind test calculations and wind tunnel dat a were in very good agreement for the surface pressure distribution, but sh owed some discrepancies in the drag prediction accuracy. In order to unders tand the reasons for this scatter, two additional computational tests were performed: 1) computation of a fuselage test case with one Navier-Stokes co de on all the different structured grids; 2) computations by all the struct ured Navier-Stokes codes on one common grid. These results have reduced the large scatter in the drag data from CFD analysis, although some discrepanc y still exists.