Hydrodynamic noise reduction mechanism of a superhydrophobic surface with different slip velocities

Abstract

Although superhydrophobic surfaces can change the flow regime of the boundary layer, most studies have focused on microscale channel flow. In this work, we use the slip boundary condition to simulate the superhydrophobic surface model on the macroscale. Flow regime changes and the hydrodynamic noise of the superhydrophobic surface model are investigated at different velocities. Results show that the superhydrophobic surface can reduce the hydrodynamic noise in the frequency range of 10–5000 Hz. When the velocity was 3.66 m/s, the noise reduction level of superhydrophobic surface model is 11.6 dB compared with that of the no-slip model. Furthermore, in the frequency range of 2000–5000 Hz, the superhydrophobic surface exhibit superior hydrodynamic noise reduction that could reach 23.4 dB. Consequently, experiments are conducted at different flow velocities to verify the noise reduction effect of the superhydrophobic surface. The experimental results show that the hydrodynamic noise is effectively reduced after the control of superhydrophobic surface. This work provides macroscale simulation results for hydrodynamic noise from a superhydrophobic surface, and indicates that hydrodynamic noise can be effectively reduced by a superhydrophobic surface.