Effects of Secondary Injection on the Cross Flow Induced Vibration of a Single Cylinder

Abstract

This paper represents an experimental investigation on the effect of a secondary injection in the vicinity of an elastically mounted smooth cylinder, on the flow induced vibration of such cylinder with the possibilities of using such injection for controlling the flow induced vibration. It was found that the effect is very much dependent on the blowing rate (ρiUi/ρU), the location of injection downstream, the cylinder and the range of reduced velocities in question.The results obtained suggest that at certain combination of injection velocities, location of injection downstream and reduced velocity, the dimensionless amplitude of vibration can be reduced by as much as 50%. However, there seems to be other blowing rates, i.e. blowing rates greater than 1, which may lead to an increase in the vibration amplitude of the cylinder. The results of this investigation show that secondary flow, if properly used, can be utilized as an effective means for controlling practical flow induced vibration.