Simulation Of Hydrofoil Cavitation Caused By Angle Of Attack And Sediment

In China,the river sediment content is high.The hydraulic machinery is often affected by the cavitation caused by the combined action of water and sediment,also reduced the efficiency and service life of hydraulic machinery.The cavitation and cavitation erosion are the important reasons of damage mechanical life.Therefore,it is of great significance and value to explore the internal flow characteristics of hydraulic machinery under cavitation and cavitation erosion conditions.In this paper,under two different attack angles for a symmetric reduced hydrofoil model,the cavitation phenomena of clear water and sediment laden flow are calculated respectively.At the same time,the effects of attack angle and sediment on cavitation performance are analyzed.The main research contents and conclusions of this paper are as follows:(1)Consult literature and collect data.In the past research,scholars' research on cavitation model and the research methods of multiphase flow simulation are summarized.(2)Modeling hydrofoil model with UG software.At the same time,the hydrofoil was placed at 3°and 9 °angles in the same flow field as the corresponding experimental data,and the mesh division and independence test were carried out respectively.(3)An integrated cavitation model and a two-phase flow model are used to simulate the cavitation,analyzing the cavitation number,cavitation phenomenon,pressure and velocity,and compared with the experimental results.It is found that the location of cavitation often corresponds to the low pressure region.The cavitation number is smaller and more cavitation.At the same time,the fluctuation of velocity is greater.Under the same conditions,the cavitation performance of high angle of attack is worse than that of low angle of attack.(4)Numerical simulation of three-phase flow in sediment laden flow.Under the condition of the same cavitation condition as that of clean water,the law of cavitation phenomenon,pressure,velocity and so on are obtained.It is found that the cavitation intensity of sediment laden flow is more serious than that of clear water.In the case of large angle of attack,the effect of water sediment interaction on cavitation is more severe than that of small angle of attack.