Aerodynamic and Acoustic Characterization of Serrated Savonius Vertical Axis Wind Turbine

Numerical simulations were conducted to evaluate the performance of straight and helical Savonius Vertical Axis Wind Turbine (S-VAWT) with serrated edges. Transient simulations were performed at different Tip Speed Ratios (TSRs) between 0.6 to 1.6. The flow structures in the turbine wake of S-VAWT were simulated using the κ-ω Shear Stress Transport (SST) Detached Eddy Simulation (DES) turbulence model. A strong agreement was observed between the numerical results and experimental data from the literature for a conventional Savonius VAWT design. Additionally, acoustic modeling was conducted using the Ffowcs Williams–Hawkings (FW-H) acoustic analogy model to determine the noise characteristics of each VAWT design.

The performance characteristics of the straight and helical Savonius VAWT with serrated edges were evaluated and compared using the coefficient of moment (c_m), coefficient of power (c_p), and noise reduction levels. The results indicate that using serrations along the edges of Savonius VAWT can lead to substantial enhancement in c_p value while achieving lower Sound Pressure Level (SPL) values, specifically at a TSR value of 0.8. In summary, a comprehensive numerical approach has shown that serrated Savonius VAWT can outperform current VAWT designs.