| With the industrialization and increasing application of smart devices,human has gradually been relying on these machineries and tools.Pumps,as one of the vital power equipment,are widely used in fields of industry,agriculture and the like.Many fields badly call for pumps being able to transport media with suspended solid particles or fibers – such as industry,agriculture,urban water supply and drainage or else – bringing about non-clogging pumps that meet higher standards.Therefore,the study and development of nonblocked pump has become the cutting edge and focus among the world.Currently,the vortex pump takes up a relatively bigger share in industrial application because of its better anti-blockage performance.But up to now,research achievements about optimizing the performance of vortex pump are mostly based on hypothesis and numerical simulation.The majority solely took the influence of geometric parameters of vaneless chamber on the circulating-flow into consideration,however they barely went a long way to study the blade type and the causation of circulating-flow.The noticeable shortage of the vortex pump is its low efficiency compared with other vane pumps.To work out the realistic law of the two-phase flow(solid-liquid)in this kind of pump,this paper takes the self-designed vortex pump as research object by means of numerical simulation and experiment.When conducting numerical simulation,the RNG6)- model is used as the turbulence model to compute static pressure,eddy viscosity,velocity,and so on.As for the setup,the vortex pump with 1/4R60L30 impeller was selected as the test pump.We recorded the internal flow through the highspeed camera and measured the real-time physical data by flowmeter,pressure gauge and tacho-torquemeter.Then,we compared the numerical results with those obtained on the setup so as to analyze the relationship between the distribution of flow pattern and the pump's performance.In the end,the flow patterns in vortex pump with every blade type(add up to 14)and their performance are compared with each other to obtain the influence of blade type on inflow.After the above steps,we go further to study the impact of circulating-flow on other flow patterns.The results are as follows: The fluid passage can be divided into two parts.Within the impeller domain,hydraulic impingement,vortices and throughflow are the main forms,while the circulating-and through-flow are dominant in the vaneless chamber.Driven by complex factors,the circulating-flows in the vaneless cavity are symmetrically arranged which can be called as main and subsidiary circulating-flow.To quantify their influences on the pump,we analogized them to vortices as their appearance on sections we selected,which contributes to a new model of inflow patterns for the vortex pump later.According to simulated results,we analyzed the impact of blade types on the distribution of flow forms,telling us that blade shape mainly has its influence on the vortices and the circulating-flow.That is,the angle or the location of kinked point on the blade will vary the distribution and size of vortices in impeller domain as well as the velocity of the entire circulating-flow in the vaneless chamber.And the vortex pump with folded blade have better performance.In view of this paper,it is possible to optimize the vortex pump through improving its blades,and this work also entitles the pump to achieve its best running state and meet the actual needs when modifying its blade shape. |
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