Effects of Non-Sinusoidal Motion and Effective Angle of Attack on Energy Extraction Performance of a Fully-Activated Flapping Foil

Flapping foil energy harvesting systems are considered as highly competitive devices for conventional turbines. Several research projects have already been carried out to improve performances of such new devices. This paper is devoted study effects non-sinusoidal heaving trajectory, pitching and the effective angle attack on extraction a flapping operating at low Reynolds number (Re=1100). An elliptic function with an adjustable parameter S (flattening parameter) used simulate various sinusoidal trajectories. The flow around simulated by solving Navier–Stokes equations using commercial software Star CCM+ based finite-volume method. Overset mesh technique model motion. applied NACA0015 following kinetic parameters: dimensionless amplitude h0 = 1c, shift between motions 90°, reduced frequency f* 0.14, αmax varying 15° 50°, corresponding in range 0 55.51° 99.51°. results show that, trajectory affects considerably performances. For reference case (sinusoidal motions, Sh S =1), best obtained attack, 40°. At small 40°), motion has negative effect. Performances improvement quite limited combined heaving/sinusoidal pitching.