| Inducer is a kind of axial flow impeller,passes through the spiral blade rotating power,increase the export of fluid energy,at the same time inducer has a prewhirl effect on fluid and can make the impeller has better ability of resistance to cavitation.The parameters of the inducer geometry have some influence on the performance,among which the blade number is one of the main geometric parameters.Therefore,this article aimed at different blade number of inducer to carry out the numerical simulation and experimental research,a two-blade and three-blade inducer were taken as the study models.The hydraulic performance,internal flow field,cavitation performance and distribution of cavitation were analyzed,and the influence of blade number on its internal flow and cavitation characteristics was revealed.The main contents are as follows:(1)The three-dimension model of inducer full flow field was established by UG software,and the fluid domain includes four parts: the inlet section,the inducer section,the cavity and the outlet section.ICEM software was used to divide the grid,and numerical simulation was performed for the inducer full flow field based on SST turbulence model and cavitation hybrid model.(2)In the non-cavitation condition,the internal flow field of the two difference blade numbers inducer were simulated numerically.The influence of blade number on the hydraulic performance of induced wheel was analyzed,It was found that the two-blade inducer had a better head.Then the inducer axial pressure distribution,blade pressure counters and streamline figure were analyzed,and it was found that the inducer pressure gradually increased along the spiral direction of the blade,and there was a low pressure zone in the leading edge of the inducer blade,and the low-pressure zone in the leading edge of the two-blade inducer was larger than the three-blade inducer.(3)In the cavitation condition,the cavitation numerical simulation of the inner flow field of the two difference blade numbers inducers was carried out.The cavitation performance curves of the two inducers were compared,and the three-blade inducer had a better anti-cavitation performance.The distribution of cavitation volume fraction of inducer under different cavitation was analyzed,and it was found that cavitation was mainly generated in the position of lock nutand blade leading edge.Then,the pressure distribution,streamline distribution and pressure pulsation inside the inducer when the critical NPSH is further analyzed.(4)The characteristic performance experiment was carried out on the two difference blade numbers inducers,and the accuracy of the numerical simulation was verified by comparison with the numerical simulation results. |
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