Effect of slurry flow rate on cavitation characteristics of deep-sea mining pump
XU Hailiang1,2*,PENG Neng1,YANG Fangqiong1,2
1. School of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan 410083, China; 2. State Key Laboratory of High Performance Complex Manufacturing, Changsha, Hunan 410083, China
Abstract：The three-dimensional fluid domain model of a two-stage deep-sea mining pump was established,then the effect of slurry flow rate on cavitation characteristics of the pump was simulated and analyzed by computational fluid dynamic based on the Fluent software, Euler multiphase flow model, Schnerr-Sauer cavitation model and RNG k-ε turbulence model.The particle size in the slurry is d=20 mm, solid volumetric concentration is CV=8%, and the pump rotational speed is n=1 450 r/min.Specially, the cavitation characteristics of the slurry pump were explored at different slurry flow rates in terms of pressure distribution curve, vapor volume fraction contour and hydraulic performance. The performance was compared with the experimental data measured by us.The aim of this study is to provide theoretical basis for the cavitation characteristics of slurry pumps.The results show that there is a notable low-pressure zone near the blade leading edge in the first stage impeller and the size of the zone shrinks with increasing flow rate.The area of vapor volume fraction sharesa similar rule to the low deep-sea pressure zone.Areverse flow phenomenon appears in the cavity, which can intensify the instability of flow field.As the flow rate increases, the net positive suction head rises and the cavitation phenomenon becomes less obvious, and its impact on the pump head is minor.
