Abstract:

The Fluent was used to solve the unsteady incompressible 2D Navier-Stokes equations for laminar flow around the airfoil. A domain dynamic mesh strategy was used on fluid domain within sliding interface to make it move with the airfoil. The strategy could ensure the mesh quality of core zone. The influence of the location of the pitching axis on the NACA0015 oscillating airfoil in aerodynamic characteristics and energy extraction performance, and the coupled effects of the location of the pitching axis and the phase difference between the two motions on the system were investigated with a Reynolds number of 1100, a pitching amplitude of 76.33°, a heaving amplitude of one chord, a reduced frequency of 0.88. The results showed that, the location of the pitching axis would influence lift characteristics, pitching moment characteristics and energy extraction performance of an oscillating airfoil. When the energy extraction performance of the system declined for the location of the pitching axis deviating from the average center of pressure, the energy extraction performance could be improved by changing the phase difference between the pitching and heaving motions.

Key words: oscillating airfoil, location of the pitching axis, phase difference, lift, pitching moment, energy extraction