Abstract
To investigate the propulsion mechanism in a narrow and deformable passage, we applied a coupling method of immersed boundary method (IBM) of body force type and finite element method (FEM). In our model, the object profile mimics a fish and the undulatory motion is not predetermined. Sinusoidal forces are given at a few nodes on the spine of the fish and it propels itself forward by the hydrodynamic force on its surface. The speed and the flow around the body are compared for different types of ambient fluid boundary conditions: an open space, a narrow channel with rigid walls and a narrow channel with deformable walls.
