An experimental investigation of novel bio-inspired curved bladed VAWTs having leading-edge tubercles for enhanced power production

Darrieus vertical axis wind turbines are an omnidirectional type of turbine. The major concern with this type of turbine is its low efficiency. The experimental study focuses on implementing a bioinspired design. Humpback Whale flippers are mimicked for a novel design of a swept curved blade with leading-edge tubercles. A NACA4412 thin cambered profile and NACA0022 thick symmetric airfoil profile are chosen for making turbine blades, and the study is performed in the subsonic wind tunnel at Reynolds numbers ranging from 15,000 to 70,000. To validate the accuracy and novelty of the model over the conventional model, performance parameters like torque and power coefficients are calculated to showcase valid improvement in performance. It is exciting to observe that curved blades with tubercle leading edge modification have shown better results. Among seven configurations of turbine blades, the model with a high amplitude to wavelength A/ \(\gamma \) $\gamma$ ratio showed more promising results than the other configurations regarding efficiency. A maximum of 35% \(C_P\) $C_P$ was obtained with the novel curved tubercle model with A/ \(\gamma \) $\gamma$ = 0.5, significantly enhancing electrical output.