Analytic Modeling of a Size-Changing Swimmer

Cephalopods use large-scale structural deformation to propel themselves underwater, changing their internal volume by 20–50%. In this work, the hydroelastic response of a swimmer comprised fluid-filled elastic-membrane is studied via an analytic formulation two coupled non-linear dynamic equations. This model self-propelled soft-body dynamics incorporates interplay external and added-mass variations. We compare against recent experiments for body which abruptly reduces its cross-section eject single jet fluid mass. Using we study impact size-change excitation on sustained swimming speeds efficiency.