| Summary: | 碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 99 === The present study aims to explore dynamical behavior of the single cylinder and the staggered cylinder arrays in shear flow by numerical simulations. The results are compared with the case in uniform flow. After the observation of the fluid-elastic vibration in the staggered cylinder arrays in the two flows. This paper investigates the effects of the spacing(P/D), mass ratio and the shear parameter on the trajectories, oscillation amplitudes among the different cylinders.
Continuity equation and momentum equations are used to solve the aforementioned problems alternatively by PISO method. Dynamic meshing techniques together with the cylinder motion equations are employed in the simulation. Under the different conditions, flow types and cylinder motion models, lock-in and fluid-elastic vibration are studied when the flow crosses the staggered cylinder arrays.
The results show that the motion and the flow field around the single cylinder is consistent with the literature. In terms of the staggered cylinder arrays in uniform flow, the oscillation is dominated by the vortex shedding, and the lock-in area in the downstream cylinders is greater than the upstream cylinders. Fluid elastic vibration occurs in the small spacing between cylinders. In shear flow, when the shear parameters are larger or the spacing between cylinders are smaller, the more likely the fluid elastic vibration of the cylinders will occur.
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