Study On Internal Flow Field Numerical Simulation And Fluid-structure Interaction Analysis Of Diagonal Flow Pump For Deep-sea Mining

Lifting pump is an important equipment in the lifting system of deep-sea mining pipeline.The internal flow condition is complex.Besides meeting the basic index,the size limit should also be considered.At the same time,in the process of practical application,there are some problems such as pump plugging,serious wear of components and vibration.Therefore,the research on the law of solid-liquid flow and the structural modal analysis of the lift pump provides the basis for guiding the design of the pump and optimizing the operation condition of the pump.The main work of this paper is as follows:The three-dimensional design method of the diagonal pump is used,and the numerical simulation of the diagonal pump is carried out after the grid number independence verification.The results show that the hydraulic performance meets the design requirements.At the same time,the internal flow field of the diagonal flow pump under different flow rates is discussed,and the optimized structural parameters are selected.Based on the numerical simulation of the hydraulic performance of the two-stage diagonal flow pump,the effects of the impeller wrap angle,the axial length of the guide vane and the guide vane wrap angle on the hydraulic performance and the flow condition in the pump are studied.By comparing the hydraulic performance and internal flow field of the original model and the optimized model,the optimal structural parameters such as impeller wrap angle,guide vane axial length and guide vane wrap angle are determined.A two-phase numerical simulation is carried out for the optimized model.The influence of particle concentration and particle size on particle aggregation,impellers and guide vanes wear,and the particle traveling time distribution is discussed.Through the analysis of the particle volume fraction and wear rate contour,it is found that the parts where the particles are most likely to gather in the normal operation of diagonal flow pump,and the parts where the impellers and guide vanes need to be thickened and protected against wear.By means of one-way fluid structure coupling method,the influence of centrifugal force and water pressure on the strength of the rotor system under different working conditions is discussed.According to compare the first critical speed with the rated speed,the results show that the pump rotor system is stable and not prone to resonance.The research results can provide a theoretical basis for the design and development of multi-stage diagonal flow pump of deep-sea mining.It also has reference significance for the optimal design of this kind of pump.