抄録
Unsteady viscous flow field around a wavy oscillating plate in highly viscous fluid is numerically studied. The Reynolds number based on the oncoming velocity and plate length is ranged from 100 to 1000. The flow around a oscillating plate is simulated by solving the full 3D unsteady Navier-Stokes equations in a primitive value formulation. The numerical scheme is based on the MAC method where the Navier-Stokes equations are solved by the time marching method on a body fitted coordinate system. Dependency of the wave number and phase velocity on the thrust and propulsive efficiency is investigated. As the Reynolds number becomes lower, the portion of the frictional resistance enlarges and the propulsive efficiency is getting small. Through the computation, it is found that there is a suitable motion to produce thrust depending on the Reynolds number. At Re=1000, the wavy oscillation with increasing amplitude is effective, while sine wave oscillation is effective at Re=100.
