Effect of a novel micro floating raft array skin on flow noise of the underwater vehicle model

Abstract Reducing the flow noise of underwater vehicles is an important topic in the fields of defense. In this paper, the flow noise reduction characteristic of a novel micro floating raft array skin (MFRAS) inspired by dolphin is studied, exploring a novel method for controlling flow noise in underwater vehicles. A simulation model based on Large Eddy Simulation (LES) and Lighthill acoustic analogy is used to calculate the flow noise of an underwater vehicle model covered with the MFRAS. The results show that the MFRAS can uniform the pressure distribution of the fluid field, increase the thickness of the boundary layer, and reduce the flow noise. At the Re L of 3.77 × 10 6 , 6.28 × 10 6 , 8.80 × 10 6 , and 11.30 × 10 6 , the sound pressure level of the model covered with MFRAS is 9.54, 7.34, 7.15, 6.49 dB smaller than that of the bare model. In addition, the flow noise reduction performance of MFRAS can be affected by its structural parameters. With appropriate structural parameter combination, the flow noise reduction performance of MFRAS is superior to equal weight free damping layer. This study demonstrates that the potential of MFRAS in controllable flow noise reduction performance and lightweight design.