Impact of frontal round jet on vortex synchronization control around a cylinder: a turbulence perspective

Abstract

The present study demonstrates that a round turbulent jet issued from a cylinder surface towards the upstream against the current can be a controlling parameter for vortex synchronization (VSC) in the wake region (WR) of the vertical cylinder. The results depict that the VSC state can be reached when the jet excitation frequency and the natural shedding frequency (NSF) are almost equal, or the jet excitation frequency is double that of the NSF. Precisely for VSC case, the turbulent production and dissipation terms of the turbulent kinetic energy budget equation contribute majorly to the total energy at the reattachment region with shifting of energy from the pressure and the turbulent diffusion terms. The enhancement of intermittency in turbulence for the VSC cases is also pertinent.