Experimental Confirmation of an Aquatic Swimming Motion Theoretically of Very Low Drag and High Efficiency

It has been established theoretically that self-propulsion of deformable bodies in ideal fluid can occur with a careful specification of the deformation mode shape. With the fluid assumed ideal, vortex shedding, rotational wake, and induced drag would not occur. The implication is that for a real fluid, provided the existence of a thin boundary layer, similarly configured bodies with the same deformation mode shape self-propel without vortex shedding, rotational wake, and induced drag. Only viscous drag effects, due to the existence of the thin boundary layer, are present and unavoidable. The motion mode in question is the little-exploited anguilliform mode exhibited in some aquatic animal swimming. The Anguilla includes the snake, eel, lamprey, and leach, among others.