Investigations into the unsteady internal flow characteristics for a waterjet propulsion system at different cruising speeds

OCEAN ENGINEERING

卷:203

Article

Huang, Renfang¹  Ye, Weixiang^2,5  Dai, Yuanxing³  Luo, Xianwu^2,5  Wang, Yiwei^1,4  Du, Tezhuan^1,4  Huang, Chenguang^1,4 

[1] Chinese Acad Sci, Inst Mech, Key Lab Mech Fluid Solid Coupling Syst, Beijing 100190, Peoples R China

[2] Tsinghua Univ, Dept Energy & Power Engn, Beijing 100084, Peoples R China

[3] Sci & Technol Water Jet Prop Lab, Shanghai 200011, Peoples R China

[4] Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China

[5] Tsinghua Univ, State Key Lab Hydrosci & Engn, Beijing 100084, Peoples R China

关键词: Waterjet;    Waterjet propulsion;    Pressure fluctuation;    Numerical simulation;   

DOI  :  10.1016/j.oceaneng.2020.107218

来源: Elsevier

【 摘 要 】

Unsteady turbulent flows in a waterjet propulsion system are investigated at various cruising speeds with the emphasis on pressure fluctuations. The numerical methodology is based on the Reynolds-Averaged Navier-Stokes (RANS) equation with the SST k-omega turbulence model and a sliding mesh technique. The head and efficiency of the waterjet pump are predicted fairly well compared with the available experimental data. The pressure fluctuates intensively in the impeller and the dominant frequency is the impeller rotating frequency with the largest amplitude near the impeller inlet. Besides, two dominant frequency components exist in the intake duct and the diffuser. A high-frequency component is caused by the rotor-stator interaction, and another component is generated by the unsteady vortex evolution in the diffuser passage and would propagate upstream to the impeller and the intake duct. Analyses based on the vorticity transport equation demonstrate the great contribution of the vortex stretching term to the vorticity distribution and evolution in the diffuser. Finally, at the cruising speed of 45 knot, the flows inside the duct are strongly affected by the impeller rotation and present a periodic prewhirl motion with the dominant frequency of the impeller rotating frequency.

【 授权许可】

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