Vortex flow patterns of a heaving foil

It is known that an oscillating foil can produce a thrust force through the generation of a reverse Kármán vortex street and this can be expected to be a new highly effective propulsion system. A heaving foil model was made and it was operated within a circulating water channel. The wake formation behind the heaving foil was visualized using PIV method and a dynamic thrust force was measured using a mini 6-axis force sensor based on force and moment detectors. We examined various conditions such as reduced frequency and amplitude in NACA 0010 profile. The vortical patterns in the wake were classified according to the wake mode and force data.