The Effect of Cylinder Blowing on Flow-induced Noise Reduction in a Cylinder-Airfoil

In this paper, the effect of blowing in a rod on the flow structure and its noise in a rod-airfoil is investigated. To this aim, the simulation of the flow around the rod-airfoil was performed using URANS equations and employing k-ω-SST turbulence model. . The prediction of the flow-induced noise is performed using F-WH analogy. Since Vortex's periodic producing is the main cause of the noise mechanism, by reducing its effect on the airfoil leading edge, the acoustic propagation reduces as well. In the present study, in order to control flow and reduce noise, the blowing active control in the rod has been used. The intensity of the blowing (I) is chosen between 0.1 and 0.5 where I is the ratio of blowing velocity to the inlet freestream flow). The results showed that increasing the blowing intensity to 0.5 reduces the noise emitted from the rod by 90% and the airfoil and rod-airfoil by 64%. In addition, by applying blowing, the lift force is increased and the drag force of the rod is reduced, which is aerodynamic favorable. In addition, the vortex shedding frequency is decreases while blowing applied.