An optimization study of passive flow control mechanism for a seashell-shaped wind turbine

Abstract

Small wind turbines have a lot of promise in areas that are remote from the power grid. For such small-scale applications, such as off-grid electricity, a spiral wind turbine (SWT), a novel type of horizontal-axis wind turbine, may be employed. Placing wind turbines within a duct is one potential method for increasing the efficiency of wind energy harvesting in low-wind urban locations. In this work, a shroud with a flange at its outlet is created using an optimization approach that attempts to maximize the coefficient of power (CP), which improves SWT performance. An evolutionary algorithm over a Kriging interpolative model serves as the optimizer in use. The shroud's shape is determined using a series of straight lines. Using the commercial code program ANSYS-FLUENT, the Reynolds-averaged Navier-Stokes (RANS) equations are solved along with the SST k–ω turbulence model to determine the turbine CP. The computational results are validated and confirmed with previously published results. The optimal shroud design introduced significant improvements in the CP when applied to the SWT, resulting in a maximum CP of 0.967 (at λ = 3.25), which is 3.6 times the maximum CP of the bare SWT (CP = 0.2668 at λ = 2.5).