Study on noise of an axial flow waterjet pump with wavy leading edge

• Published in: Ocean engineering 2022-10, Vol.261, p.112117, Article 112117
• Main Authors: Guo, Zhiwei, Xia, Weipeng, Qian, Zhongdong
• Format: Article
• Language: English
• Subjects: Noise; Waterjet pump; Wavy leading edge
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2022.112117

The effects of wavy leading edge on noise of an axial flow waterjet pump are investigated by using numerical simulation method. Based on bionics, five wavy leading edges with different combinations of wavenumber and amplitude are proposed. The physical mechanism is also revealed. The results show that the rotor with wavy leading edge does not change the dominant frequency of the noise, but reduces the amplitude. The optimal combination of wavenumber and amplitude in the study is 4/s (s is spanwise length) and 0.12C (C is the averaged chord length). The reason is that the wavy leading edge changes the pressure distribution of the blade, resulting in a radial pressure gradient. Meanwhile, vortex pairs around the leading edge of the blade occur. The vortex pairs cause the momentum exchange of the fluid in the boundary layer and outside the boundary layer, which makes the velocity distribution more uniform. In view of turbulent kinetic energy, the wavy leading edge can greatly reduce the turbulent kinetic energy in rotor under large mass flow rates. Therefore, the wavy leading edge may be applied to design the rotor of the axial flow waterjet pump to reduce its pressure pulsation and noise. •The wavy leading edge has positive effects on noise.•The optimal combination of the amplitude and wavenumber is 4/s and 0.12C.•The momentum exchange caused by the vortex pairs is the main reason for noise reduction.