Bluff Body Wake Stability Enhancement by Mean of Non-Isothermal Blowing

The influence of blowing or suction from the surface of a porous circular cylinder in crossflow onto the dynamics of its near wake is numerically studied for flows close to the onset of the wake vortex shedding regime at a Reynolds number of 49. Two cases are considered: the blowing may be at the same temperature as the mainstream fluid or at a lower temperature. The latter case is mainly motivated by arguments of thermal protection of the cylinder from a hot incident flow. Local and global instability growth rates are investigated under the effect of different blowing locations and temperatures. It is shown that both blowing and suction have a dramatic impact on the absolutely unstable region, thus affecting the wakr behavior, eventually leading to the suppression of vortex shedding.