Vortex Method for the Analysis of Complex, Unsteady and Vortical Flows around a Swimming Fish
Although it is well known that the modes of undulatory locomotion of fish swimming provide high speed and high drive efficiency, it is hard to understand the propulsion mechanism of fish directly from living things. In the present study, in order to investigate hydrodynamic characteristics of the swimming modes, numerical simulation of flows around a deforming body of a rainbow trout which belongs to the kind of fish of subcarangiform undulatory swimmers was performed by using a Lagrangian vortex method. In this simulation, the basic configuration of the fish body is modeled with use of a NACA type airfoil, and the mode of undulatory motion is numerically given by a function obtained from observation of actual fish swimming. As a result of the present study, the relation between characteristics of propulsion force acting on the fish body and formation of complex vortex structures are clarified.
Pietro VINCENZINI and Salvatore GRAZIANI
K. Kamemoto and A. Ojima, "Vortex Method for the Analysis of Complex, Unsteady and Vortical Flows around a Swimming Fish", Advances in Science and Technology, Vol. 58, pp. 183-192, 2008