MODULATION OF RECIRCULATION ZONE BEHIND A CUBICAL OBSTRUCTION BY THE VERTICALLY PLACED TURBULENT MULTIJETS IN THE FORM OF SHOWER

Abstract

The present numerical work reports the application of jets for modulating and eradicating the recirculation zone in the wake region behind a fully submerged two-dimensional square cross-section bluff body for high Reynolds number flow. The wake region of the bluff body is characterized by a strong recirculation zone and vortex shedding, leading to unwanted vortex-induced vibrations that may instigate structural damage. Jets of varying Reynolds number and center-to-center distance are explored to look into the most effective jet Reynolds number and jet spread in completely modulating the recirculation region. The numerical simulation is based on a two-phase volume-of-fluid model with open channel boundary conditions. The standard k-ω SST two-equation turbulence model is applied to close the time-averaged-momentum and continuity equations. The negative mean streamwise velocity signifies the recirculation region, and streamline contour plots are made to identify it. The variation in discharge velocity of the jet series is carried out for reallocation or complete disappearance of the recirculation region.