Unsteady pressure field around oscillating prism predicted by LES

Unsteady velocity-pressure fields around an oscillating square prism are analyzed by means of Large Eddy Simulation (LES). The accuracy of the numerical results is assessed by comparing them with the experimental results of Bearman et al.[3]. The prism is forced to oscillate in a sinusoidal motion in the x₂ (lateral) direction. In order to incorporate the influence of the body motion, an inertia force term, whose magnitude is equal to the acceleration of the body, but with the opposite sign, is added to the transport equation of u₂, as an external force at each grid point of the fluid. The reduced velocity, U_o/N_pD, in this study ranges from 7.5 to 10.0. It was confirmed that the numerical results successfully reproduce the lock-in phenomena in this range. Furthermore, the results of LES showed a good agreement with the results of experiment, in terms of: 1. 1) the phase angle between the displacement of the oscillating prism and the negative pressure acting on the side face, and 2. 2) the correlation between pressures across the side face.