Assessment of RANS Turbulence Models for a Strut-Wing Junction

Multidisciplinary Design Optimization (MDO) studies show the Strut/Truss Braced Wing (SBW/TBW) concept has the potential to save a significant amount of fuel over conventional designs. For the SBW/TBW concept to achieve these reductions, the interference drag at the wing strut juncture must be small compared to other drag sources. Computational Fluid Dynamics (CFD) studies have concluded the interference drag is small enough for the TBW concept to be practical. However, the turbulence models used in these studies have not been validated for transonic, high Reynolds number, junction flows. This study intends to assess turbulence models by comparing drag and surface streamlines obtained from experiment and CFD. The test model is a NACA 0012 fin at Mach number of 0.75 and a Reynolds number of 6 million with varying angle of attack. 

The study shows CFD over predicts separation. The reasons for this discrepancy is likely the turbulence models employed.