Influence Of Dynamic Parameters On Interactive Erosion And Cavitation Wears Of Impeller

High-speed sediment flow generated erosion wear on fluid mechanical impeller;and the axial pressure gradient caused by the rotation impeller, which crushed thebubble evolution from the water, formation pressure impact result in cavitation wear,so there are interactive erosion and cavitation wears in fluid mechanical workingconditions. The interactive wears widespread in Engineering cause the equipmentslow efficiency, intensifying vibration and frequent maintenance, which is one of themain factors that damage the fluid machine. Moreover, the interaction process iscomplex and many factors affect the wear, it has become a difficult but popularresearch for the domestic and foreign scholars.Simulating the actual working conditions of the water turbine, this paper takesthe fluid machinery impeller as the research object. The effect of fluid pressure,impacting angle, impacting speed three dynamic parameters on the interactive wearsis studied by means of the theory of fluid dynamics, tribology, material science andthe method of combining the numerical analysis and experimental research.(1) In this paper, the wear theory of fluid machinery, numerical analysis methods,research status of the combined effect of erosion and cavitation are reviewed, and theresearch source, content and plan of the project are put forward.(2) The effect of three dynamic parameters on the interactive wears is researchedin this paper, based on the numerical analysis method,. With PRO/E software, thenumerical analysis model of the interactive wear is established based on the rotatingdisc wear test rig. After dividing the grid by the GAMBIT software, the generatedmesh file is imported into the FLUENT software for numerical analysis of interactivewear in three-phase flow. And the contours of total pressure, the vapor phase volumeratio and the sand concentration are obtained under the different fluid pressures,impacting angles and impacting speeds.(3) The experimental study of dynamic parameters for affecting the interactivewears. The interactive wear test scheme is designed, and the test is carried out on therotating disc wear test rig. The effects of fluid pressure, impacting angle andimpacting speed on weight loss ratio, wear scar distribution and microscopicmorphology of the specimen are analyzed according to the experimental results. Therelation curve between weight loss and impacting angle of the40Cr specimen is obtained by simulating the experimental data; and the mathematical expressionsbetween weight loss and fluid pressure of the40Cr specimen is also obtained, underthe special working condition of interactive wear.(4) The effects of dynamic parameters on the interactive wear are analyzed,combining with the numerical analysis and experimental results. The fluid pressurehas a great effect on the interactive wear, through influencing the bubble density anddistribution in the flow field. The failure mode of the interactive wear is determinedby the impacting angle, and the relationship of impacting speed and the damage extentof interactive wear is proportional.