Experimental Study And Numerical Simulation On Gas-liquid And Solid-liquid Two-phase Flow In Vortex Pump

In order to prove up the law of liquid-solid two-phase flow in vortex pump,in reference to previous studies,based on the appropriate choice of model pump, Numerical simulation and experimental researches were used.The main works and conclusions are showed as following.Test transport of gas-liquid,solid-liquid two-phase flow when the pump performance and the internal two-phase flow field was numerically simulated.It can be provided a scientific basis for improving the actual efficiency of vortex-pump,expanding the application range,completing the internal flow model. Present research states of vortex pump and gas-liquid and solid-liquid two-phase flow were introduced simply.The main works and conclusions are showed as follow:Described vortex pump hydraulic performance of components,on this basis,select the test-bed to meet the measurement requirements of the model pump.Pro/E was applied to sculpt the model pump.The unstructured grids were generated in the area of flow passage in the pump.This paper analyzes situation of cavitation in vortex pump and centrifugal pump in detail,obtaines a number of anti-cavitation performance and gas-liquid mixed transportation of two kinds pumps.Through the cavitation experiment of modeling, Calculate changing trends of the NPSHc curve with the flow q_v.On this basis,assuming air as the bubbly flow,through the Characteristic test of gas-Liquid,obtains performance change rules of flow,head and efficiency.In the whole flow passage,the air concentrated in the wheel hub office to form a dense cluster of bubbles.The mechanism and influence of the existence of gas phase on the performance of vortex pump were explored through cavitation test and the Characteristic test of gas-liquid is compared,the results proves that vortex pump can Transient Gas-liquid Two-phase.In order to further study the solid-liquid two-phase flow mechanism in vortex pump,the interior pump flow with the vegetable seed,the wheat,the soybean by means of varying particle size and concentration in the working medium.The mechanism and influence of the existence of solid phase on the performance of vortex pump were explored through the experimental analysis on the variation of H,ηand NPSH.The distribution of pressure and particle concentration was used to analyze the influence of particle size and initial volume fraction of solid phase on particle motion,pressure and solid-phase distribution in the pump.It is concluded that:for the same particle diameters,the difference of the inlet and outlet total pressure declines with the increase of sandy volume fraction,the H andηdecreased;for the same sandy volume fractions, the difference of the inlet and outlet total pressure declines with the increase of particle diameter,the H andηdecreased.Mixture multiphase flow model and modified k-εturbulent model were adopted to simulate internal Gas-Liquid and solid-liquid two-phase flow field at the best efficiency behavior of pump;Impeller and volute have been the internal flow cavity region and the velocity and static pressure distribution.The numerical calculation is verified by comparing with expremental result.