Large-eddy simulation of a full-scale underwater energy storage accumulator
CFD, Energy storage, LES, Underwater, Vortex
Underwater energy storage provides an alternative to conventional underground, tank, and floating storage. This study presents an underwater energy storage accumulator concept and investigates the hydrodynamic characteristics of a full-scale 1000 m3 accumulator under different flow conditions. Numerical simulations are carried out using an LES turbulence model. Time-averaged and transient flow structures and force characteristics are analyzed. The results show that the vortex structures are complex and scale-rich, but periodic vortex shedding can still be identified. The shedding frequency is consistent with the fluctuation of the lift force in the cross-flow direction. A dominant Strouhal number of 0.18 is found. The mean drag and lift coefficients stabilize at 0.45 and 0.60, respectively, and are insensitive to Reynolds number variation. Modal analysis shows that the natural frequency of the accumulator falls between 27 and 48 Hz and is much higher than the vortex shedding frequency. Thus, for the accumulator model investigated in this study, the risk of vortex-induced vibration (VIV) fatigue damage is very low.
Wang, Zhiwen; Wang, Jinshun; Cen, Haoyang; Ting, David S.K.; Carriveau, Rupp; and Xiong, Wei. (2021). Large-eddy simulation of a full-scale underwater energy storage accumulator. Ocean Engineering, 234.