Free swimming of an elastic plate plunging at low Reynolds number

We use three-dimensional computer simulations to examine the free swimming of an elastic plate plunging sinusoidally in a viscous fluid with a Reynolds number of 250. We find that the free swimming velocity is maximized when the swimmer is driven near the first natural frequency leading to larger swimmer deformations, and that the free swimming velocity is nearly linearly related to the trailing edge displacement. The maximum swimmer performance is found at a non-resonance frequency. The maximum performance takes place when the swimmer exhibits a deformation pattern in which the transverse displacement of the swimmer's center of mass is minimized, which in turn reduces viscous losses.