Large eddy simulation of passive jet flow control on the wake of flow around a circular cylinder

This study presents a passive jet flow control method to suppress the wake of a circular cylinder based on a computational fluid dynamics (CFD) numerical simulation at a high Reynolds number of 5.0 x 10(4). The investigation mainly focuses on the control effectiveness of the pattern of jet holes on the hollow pipe. First, the three-dimensional (3D) flow past a circular cylinder at a Reynolds number of 3900 is addressed based on the large-eddy simulation (LES) method to validate the feasibility of a numerical simulation. Then, the control effects of the passive jet flow on the aerodynamic forces and the wake flow of the circular cylinder are studied at different directions, angles, and heights of the jet holes. An optimal parameter scheme for suppressing the wake of a circular cylinder is then determined according to a comparison of the control effectiveness of the aerodynamic forces. The results indicate that the jet flow from the backward holes of the circular cylinder effectively separates the shear layers rolled up on both sides of the circular cylinder, which forces the vortex formation region downstream. This control measure can dramatically reduce the aerodynamic forces and suppress the wake of the circular cylinder. (C) 2019 Elsevier Ltd. All rights reserved.