Effects of the Fuselage and Tunnel Walls on Correlation of CFD/CSD Computations and Test Data

Coupled CFD/CSD calculations were conducted using Helios and RCAS for an isolated rotor, in the presence of a fuselage, and in a wind tunnel. Four test points were analyzed each in an open domain, in a wind tunnel, with, and without modeling the Large Rotor Test Apparatus. Airloads compared very well with test data for the open domain. Effects of modeling wind tunnel walls and the fuselage body were consistent with previously reported results using different CFD and CSD software. Modeling wind tunnel walls was found to have very little affect on the airloads but increased the computation time by a factor of two over an isolated rotor in an open domain. The presence of the fuselage in the calculation caused an increase peak airloads in the second quadrant near 180 deg azimuth. Also, a wake interaction affecting the pitching moment airloads at 40% radial station that was observed in previously published calculations and is present in some of the wind tunnel data was observed when the fuselage was modeled in CFD.