Numerical investigations of the energy performance and pressure fluctuations for a waterjet pump in a non-uniform inflow

RENEWABLE ENERGY

卷:153

Article

Luo, Xianwu¹  Ye, Weixiang¹  Huang, Renfang²  Wang, Yiwei²  Du, Tezhuan²  Huang, Chenguang² 

[1] Tsinghua Univ, Dept Energy & Power Engn, State Key Lab Hydrosci & Engn, Beijing 100084, Peoples R China

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

关键词: Waterjet pump;    Energy performance;    Pressure fluctuation;    Numerical simulation;   

DOI  :  10.1016/j.renene.2020.02.081

来源: Elsevier

【 摘 要 】

As a way of exploitation and utilization of ocean energy, the waterjet pump is used in a wide range of high-speed marine vessels over 30 knot. This paper aims to investigate the mechanism of the energy loss and pressure fluctuations caused by the non-uniform inflow for a waterjet pump. Unsteady internal flows inside the waterjet pump are simulated using the Reynolds-averaged Navier-Stokes equations with the SST k-omega turbulence model. The predicted pump head and efficiency are in reasonable accordance with the experimental data. The inflow non-uniformity would decrease the hydraulic head, efficiency and increase the axial force fluctuations in the impeller, causing large pulsations in the unsteady energy performance. Based on analyses of the energy loss, the turbulent kinetic energy production and the diffusion of the Reynolds stress are major sources of the energy loss in the waterjet pump. The non-uniform inflow induces a dramatic energy loss in the intake duct and diffuser with an apparent flow separation observed near the trailing edge of the diffuser blade. Due to the inflow non-uniformity, the pressure fluctuates violently at the impeller rotating frequency (f(n)) in the intake duct, impeller and near the diffuser inlet, but a dominant frequency of 2f(n), is generated by the unsteady flow separation near the diffuser outlet. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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