Modeling Turbulence Control Effect of the SINHA Flexible Composite Surface Deturbulator

Abstract

The effect of treating an aerodynamic surface with a Flexible Composite Surface Deturbulator (FCSD) has been modeled using Loci/CHEM, a RANS CFD code. The FCSD is postulated to control turbulent mixing by utilizing its ridged substrate to break up long wavelength flow instabilities imposed on its flexible surface. To mimic this cost-effectively, a turbulence length scale limiter has been selectively applied to the k-ω turbulence model, thereby constraining the length scale of turbulence production. CFD predictions of a Deturbulator treated deflector oriented 30 degrees with respect to the freestream validate the wave breakdown effect when compared to wind tunnel measurements. Simulations of a S809 wind turbine airfoil have yielded modified 20% lower low-skin friction marginally separated boundary layers over 95% of the chord on the upper surface, and a 2% increase in L/D.