RODEBAUGH, Gregory P*; LIEW, Chun Wai; LONG, John H; ROOT, Robert G; Lafayette College; Lafayette College; Vassar College; Lafayette College: Lift and thrust in carangiform swimming: An integrated model of a pumpkinseed sunfish (Lepomis gibbosus)

A novel computational approach, one which allows for dynamic evolution of the fish fluid interface in response to force balance, is used to provide insight into carangiform undulatory locomotion. A computer simulation to model the swimming of a sunfish allows dynamic interaction of the interior mechanics of the fish and the fluid dynamics of the surrounding water. The fluid model is Lagrangian, involving impulse points that react to body forces and fluid forces. These points act as the fish-fluid interface and contribute to the viscosity. The model incorporates vortex points which react to only fluid forces. With this method, the fish being modeled doesn�t require prescribed deformation or even a prescribed path. Realistic flow allows comparison of the lift and thrust generated by the fish whose undulations are controlled by muscle contractions. Thus the relative contribution of these two forces and the overall efficiency of the locomotion can be analyzed. Supported by National Science Foundation grant DBI-0442269.