The Suppression Effect of the Hydrodynamic Noise from Airfoil Structure by Suction Technique

In this paper, we have proposed a new method to control the hydrodynamic noise from airfoil structure by the suction technique. A set of suction holes are placed on the front edge of the airfoil structure. Then, the fluid is transported into the tail or the transition zone because of the pressure difference. Flow field around the airfoil structure has been controlled, thereby the hydrodynamic noise has been attenuated. We have used the large eddy simulation to calculate the flow field. The hydrodynamic noise has been calculated by the Lighthill’s acoustic analogy and the combination of the finite element and infinite element method. We have investigated the noise reduction effect of the position, diameter and period with the hole. The results indicate that the suction hole can reduce the turbulent fluctuation pressure which is the main source of the hydrodynamic noise. The noise reduction effect can reach more than 6dB in the frequency range from 10Hz to 1500Hz. The suction technique in our work can provide a new idea for the hydrodynamic noise control of underwater vehicles.