摘要
In order to reveal the regularity of unsteady flow of centrifugal pump under different cavitation stages,a visual closed test-bed is built to collect signals such as the distribution of cavitation bubbles at the impeller inlet and external characteristics,etc.in the process of cavitation of centrifugal pumps.Combined with the shape and distribution of bubbles captured by high-speed photography,the cavitation stage of the centrifugal pump is divided.In addition,the variation of vorticity distribution,pressure pulsation and radial force of centrifugal pump under different cavitation stages are studied using the standard κ-ε turbulence model and the Kunz cavitation model.Main contributions are as follows:The cavitation bubbles can absorb the energy of vortex core to a certain extent and increase the volume of vortex core.Cavitation bubbles can also block the flow-path and induce the distortion of the internal flow field,resulting in unstable pressure waves that cause a significant increase in pressure pulsation rate.Besides,with the development of cavitation,the radial force on the impeller tends to remain invariable first and then decrease,and trajectory of the radial force changes from closed to open.
In order to reveal the regularity of unsteady flow of centrifugal pump under different cavitation stages, a visual closed test-bed is built to collect signals such as the distribution of cavitation bubbles at the impeller inlet and external characteristics, etc. in the process of cavitation of centrifugal pumps. Combined with the shape and distribution of bubbles captured by high-speed photography, the cavitation stage of the centrifugal pump is divided. In addition, the variation of vorticity distribution, pressure pulsation and radial force of centrifugal pump under different cavitation stages are studied using the standard k-ε turbulence model and the Kunz cavitation model. Main contributions are as follows: The cavitation bubbles can absorb the energy of vortex core to a certain extent and increase the volume of vortex core. Cavitation bubbles can also block the flow-path and induce the distortion of the internal flow field, resulting in unstable pressure waves that cause a significant increase in pressure pulsation rate. Besides, with the development of cavitation, the radial force on the impeller tends to remain invariable first and then decrease, and trajectory of the radial force changes from closed to open.
基金
supported by the National Key Research and Development Program of China(2017YFC0804107)
National Natural Science Foundation of China(No.51879122,51779106,51509111)
the association innovation fund of production,learning,and research(BY2016072-01)
Zhenjiang key research and development plan(GY2017001,GY2018025)
the Open Research Subject of Key Laboratory of Fluid and Power Machinery,Ministry of Education,Xihua University(szjj2015-017,szjj2017-094,szjj2016-068)
Sichuan Provincial Key Lab of Process Equipment and Control(GK201614,GK201816)
the Advanced Talent Foundation of Jiangsu University(15JDG052)
a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
Jiangsu top six talent summit project(GDZB-017)
