RANS CFD Based Analysis of Low Speed Wind Tunnel Tare and Interference and Wall Corrections for Supersonic Aircraft Configurations

Abstract

RANS CFD simulations were used to analyze the low speed wind tunnel corrections that wereapplied to the wind tunnel tests of a proposed commercial supersonic transport aircraft. The wind tunnel data used as reference and comparison for the CFD simulations was generated from the NASA SCALOS program’s testing at the University of Washington’s Kirsten Wind Tunnel. Three different configurations were studied, a cranked delta wing, and two full 3-surface configurations: a low tail and a T-tail. A series of simulations with the wind tunnel models in free air were performed to provide a baseline comparison between the fully corrected wind tunnel data and the CFD free air simulations. A CFD investigation into the 3-step T&I process used to remove the effects of the model mounting system was performed. The CFD investigation consisted of simulating all 3 of the steps of the experimental T&I process: upright, inverted, and inverted with image support system. The 3-step process was then applied to the CFD simulations and was compared to a direct simulation of model in the tunnel without the support system present. The results showed that the T&I process matched closely with a simulation of the model without the support system in the tunnel. Following, an analysis of Shindo’s wall and blockage corrections was performed to determine how well these traditional corrections apply to the large delta wings typical for supersonic aircraft configurations. It was found that the wall corrections produced from CFD generally produced corrections of greater magnitudes than the conventional methods suggested for this class of aircraft geometries.