Suppression of the Hydrodynamic Noise Induced by the Horseshoe Vortex through Mechanical Vortex Generators

Autor: Yongwei Liu, Hongxu Jiang, Yalin Li, Dejiang Shang
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Applied Sciences, Vol 9, Iss 4, p 737 (2019)
Druh dokumentu: article
ISSN: 2076-3417
DOI: 10.3390/app9040737
Popis: The hydrodynamic noise from the horseshoe vortex can greatly destroy the acoustic stealth of underwater vehicles at low frequency. We investigated the flow-induced noise suppression mechanism by mechanical vortex generators (VGs) on a SUBOFF model. Based on the numerical simulation, we calculated the flow field and the sound field of the three shapes of mechanical VGs: triangular, semi-circular, and trapezoidal. The triangular VGs with an angle of 30° to the flow direction achieved a better noise reduction. The optimum noise suppression is 8.93 dB, when the distance from the triangular VGs to the sail hull’s leading edge is 0.1c, where c is the chord length. The noise reduction mechanism is such that the mechanical VGs can destroy the formation of the horseshoe vortex at the origin and produce counter-rotation vortices to weaken its intensity. We created two steel models according to the simulation, and the experimental measurement was carried out in a gravity water tunnel. The measured results showed that the formation of the horseshoe vortex could be effectively inhibited by the triangular VGs. The results in our study can provide a new method for hydrodynamic noise suppression by flow control.
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