Experimental and computational investigation of wake induced vibration

The use of non-turbine systems to generate hydropower energy has drawn the attention of researchers. In the current paper, Wake Induced Vibration (WIV) is experimentally and numerically studied. For this purpose, two circular cylinders were arranged in a tandem in a water channel; the upstream cylinder was fixed and the downstream one was supported by a virtual elastic base. Force and displacement measurements were conducted on the downstream cylinder in a transitional flow regime, Re = 2,00015,000. The effects of the longitudinal and lateral distances between the cylinders on the dynamic response of the WIV were investigated. It is shown that WIV can occur outside the frequency of the Vortex Induced Vibration (VIV), resulting in a higher potential of energy harnessing. The results reveal that the efficiency of power generation from WIV depends on the position of the downstream cylinder, and it is a function of the Reynolds number. In addition, Computational Fluid Dynamic (CFD) studies were performed using a Scale Adaptive Simulation (SAS) model to analyse the flow characteristics around the cylinders. The lift, displacement amplitude and frequency of oscillation calculated by the numerical modelling are in a reasonable agreement with the experimental data.