Numerical Simulation Of Solid-liquid Two-phase Flow In Centrifugal Pump Based On The Particle Stress Analysis

Solid-liquid two-phase centrifugal pump is one of the important hydraulic machinery. Withthe development of the national economy, it is widely used in various fields such as waste watertreatment, urban water supply, petrochemical transportation, water dredging and agriculturalirrigation. However, with the widely use of the centrifugal pump in practical engineeringsituations, many deficiencies of it emerged: excessive energy consumption and low efficiencyoccurs when it at off-design conditions, flow components severe wear lead to poor reliability.For the reason of the complex flow pattern in two-phase flow, it is essential tosystematically study the law of two-phase flow. It will improve the study of two-phase flowtheory and further improve the design of hydraulic machinery. When the practical application hasmore stringent requirements for the design, only relying on the experience to design the pumpcannot precisely guarantee the hydraulic performance. So, based on the numerical simulation ofthe internal flow of the pump further research is significant to design a high-performance. It canprovide a theoretical reference for designing solid-liquid pump which is stable and has lowpower consumption.The research object of this paper is solid-liquid two-phase centrifugal pumps. Interactionbetween the liquid and solid particles is considered. The discrete particle model is applied tocalculate the motion of particles and the particle trajectories within flow field, the wear of theflow components from solid-liquid two-phase is also simulated. The main content of this paper isas follows:1. Using Pro/E to create the model of the centrifugal pump, the software ICEM is used togridding the model. Finally, the CFD software Fluent was applied to calculate the watercondition and solid-liquid two-phase flow conditions in the centrifugal pump separately. At lastthe results were analyzed.2. Internal force of the particle is analyzed, then the forces were compared with the flowresistance. Scale analysis was also carried out to investigate the relationship between the particlediameter and forces, based on this, the calculation model of the two phase flow were determined.3. The numerical simulation and results validation of the solid-liquid two-phase flow in thecentrifugal pump were analyzed. At first, Mixture model was used to simulate internal flow field, Then DPM model was used. Particles were treated as discrete phase. The motion of particles inthe solid-liquid two-phase flow was analyzed and the particles track characteristics were alsostudied. Based on the analysis, the pressure distributions are almost the same, with the increasingof the particle diameter in the flow channel decreased. Under different diameter, particletrajectory is different, when the particle is small, the crash frequency with impeller is small, thenumber that particle collide with the impeller increase with the increasing of particle diameter.To the erosion velocity ratio and particle concentration, it can be found that with the increasingof the volume fraction, the erosion velocity ratio on the wall of the impeller flow channelincreases. But by contrast with the increasing of the particle diameter, the ratio decreases. Thetrend of erosion velocity ratio on the wall changes with the position.