Numerical simulation of flow over a circular cylinder with a splitter plate near a moving wall

摘要

The flow past a circular cylinder with a splitter plate (CCSP) above a moving wall is simulated numerically in this paper. A large-eddy based lattice Boltzmann model is used to calculate the turbulent flow. The flows are simulated in the range of gap ratios (GID) from 0.1 to 3.0 and Reynolds number from 200 to 400, respectively, where G is the gap between cylinder and wall, D is the diameter of cylinder. The mechanism of the vortex shedding suppression near a moving wall is analyzed. Vorticity contours are demonstrated to reveal the wake flow patterns and the suppression of vortex generation. The vortex shedding from lower side of the CCSP system completely disappears when the gap ratio is less than 0.2. As gap ratio decreases from 3.0 to 0.1, the vortex shedding frequency increases and reaches the summit firstly, and then decreases for the gap ratio decreasing continuously. Compared with the near wall case which is without splitter-plate, the drag and lift coefficients of CCSP system are reduced significantly. The results. are in good agreement with the previous experiment and numerical simulations. (C) 2016 Elsevier Ltd. All rights reserved.