Evaluation of Rans Turbulence Models for Turbulent Flow over Nrel S809 Airfoil

Year 2019, Volume: 7 , 76 - 86, 24.11.2019

Bouabdellah Abed Abdelouahab Benzerdjeb Habib Achache Abiddine Debab Mohamed-kamel Hamıdou

Abstract

In this presented work, a numerical investigation was conducted to evaluate the performance of RANS turbulence models implemented in ANSYS CFX to predict flow field and aerodynamic characteristics of the NREL S809 Airfoil. The simulations were carried out with ANSYS CFX R18.2 (academic version). The blade geometry was simplified into a 2D airfoil and the flow analysis around the profile was conducted at various angles of attack equal to 0°, 5.13°, 9.22°, 11.24° and 20.15°, at a constant and same Reynolds number equal to 2x106. In this paper, the turbulence flow patterns and separation around the profile were represented using the most turbulence models used in CFD codes, the standard k-ε and its modifications RNG k-ε. The moment coefficient (Cm), the lift coefficient (Cl) and the drag coefficient (Cd) were determined and plotted as a function of the angle of attack. The pressure distributions around this profile, for each angle of attack, were also presented. The results and the plots obtained have shown good agreements with published experimental results. From the simulations, the two turbulence models provided near prediction to the experimental values at low angle of attacks, but over predict the Cd values. Calculations have also shown that the standard k-ɛ model and RNG k-ɛ model produced similarly results but with partly differences in pressure magnitude.

Keywords

NREL S809 Airfoil, CFD simulations, RANS turbulence models, Aerodynamic characteristics

References

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