Abstract
The propulsion speed and efficiency of actively swimming flexible fish like hydrofoil are investigated numerically. The finite difference method based on Airbitraly-Lagrangian and Eulerian method with moving deformed mesh is employed and translational and rotational equation of motion of the body are solved to determine the position of the gravitational center of the body. As the results of this investigation, it was cleared that the rotational motion greatly influenced the propulsion. Propulsive speed decreased 25 percent and efficiency increased 50 percent than the past method that fixed the lateral and rotational motion.
