Incompressible Navier-Stokes Computation of the NREL Airfoils Using a Symmetric Total Variational Diminishing Scheme

Abstract

The purpose of this paper is to present a numerical study of flow fields for the NREL S805 and S809 airfoils using a spatially second-order symmetric total variational diminishing scheme. The steady two-dimensional flow is modeled as turbulent, viscous, and incompressible and is formulated in the pseudo-compressible form. The turbulent flow is closed by the Baldwin-Lomax algebraic turbulence model. Numerical solutions are obtained by the implicit approximate-factorization method. The accuracy of the numerical results is compared with the Delft two-dimensional wind tunnel test data. For comparison, the Eppler code results are also included. Numerical solutions of pressure and lift coefficients show good agreement with the experimental data, but not the drag coefficients. To properly simulate the post-stall flow field, a better turbulence model should be used.

Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD

“…Here the calculation is not adequately capturing the suction-side pressure. This is the same discrepancy found by Yang, et al (1994) and Chang, et al (1996). Table 1 compares the aerodynamic coefficients for these same three cases.…”

“…There was some underprediction of Cp over the forward half of the upper surface for both airfoils in vicinity of a = 5". In their 1994 work (Yang, et al, 1994), they were able to get good agreement between the 5.13" experimental data and a calculation at a = 6" for the S805. This suggested experimental error as a possible explanation for the underprediction.…”

“…Recent applications of CFD to solve the Mavier-Stokes equations for wind-turbine airfoils are reflected in the works of Yang, et al (1994Yang, et al ( , 1995 and Chang, et al (1996). They used their in-house code to solve the 2-D flow field about the S805 and S809 airfoils in attached flow (Yang, et al, 1994;Chang, et al, 1996) and the S809 airfoil in separated flow (Yang, et al, 1995)., Computations were made with the Baldwin-Lomax (1978), Chein's (1982) low-Reynolds-number k-E, and Wilcox's (1994) low-Reynolds-number k -o turbulence models.…”

“…They used their in-house code to solve the 2-D flow field about the S805 and S809 airfoils in attached flow (Yang, et al, 1994;Chang, et al, 1996) and the S809 airfoil in separated flow (Yang, et al, 1995)., Computations were made with the Baldwin-Lomax (1978), Chein's (1982) low-Reynolds-number k-E, and Wilcox's (1994) low-Reynolds-number k -o turbulence models.…”

Numerical Analysis of Fluid Flow in an Internal Turbine Blade Cooling Passage

“…The code that is being used for this study is a pseudo-compressible code that uses a spatially second-order accurate TVD (Total Variational Diminishing) scheme developed at Michigan Technological University (MTU). This code has previously given excellent results for other geometries, in particular, wind turbine airfoils (Yang et al,1994b). The original version of the code was developed for single-block meshes.…”