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Unsteady flow over offshore wind turbine airfoils and aerodynamic loads with computational fluid dynamic simulations
Abbaspour, M.; Radmanesh, A. R. & Soltani, M. R.
Abstract
The first notable megawatt class wind turbine,
which was the pioneer of improvement in the blade performance
in large wind turbines, appeared in Vermont.
Nowadays, modern wind turbines are using blades with
multi-airfoils at different sections. In this study, in order to
indicate the best airfoil profile for the optimum performance
in different sections of a blade, five popular airfoils,
including S8xx, FFA and AH series, were studied. On the
large-scale profile, shear stress transport K–ω model was
applied for the simulation of horizontal axis wind turbines
for different wind speeds. The aerodynamic simulation was
accomplished using computational fluid dynamic method,
which in turn is based on the finite volume method, and
semi-implicit method for pressure-linked equations algorithm
is used for pressure–velocity coupling. The governing
equations applied in this simulation are the unsteady
Reynolds-averaged Navier–Stokes equations. The aerodynamic
coefficients of lift and drag were calculated at different
angle of attacks and different wind speeds. The
results were validated by EPPLER code, XFOIL and
experimental data of the US National Renewable Energy
Laboratory. The results showed that S818 profile is the best
profile in terms of gaining the highest lift coefficient with
the lowest angle of attack at the root of the blades. The
findings also indicated that the selected model can predict
the exact geometry with a high precision.
Keywords
Wind turbine; Computational fluid dynamic; Unsteady aerodynamic simulation; National Renewable Energy Laboratory
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