Fluid-structure Interaction Numerical Analysis Of Francis Runner Blade

Francis turbine runner blades and viscous fluid vibration interaction will not only stimulate leaf blades, but also lead to local stress concentration, excessive strength, resulting in fatigue fracture of blades, power failure and other events. The fluid flow induced strong vibrations of Francis hydro turbine unit occur frequently both at domestic and foreign water-power stations. They are ubiquitous that induced structure failure and reduction of turbine operating life, and finally endangered the safety operation of the turbine unit.Focusing on the current situation of station runner blades fluid-structure interaction analysis, this paper used Unigraphics modeling software and double cubic uniform B-spline surface method to achieve the blade surface fitting, to resolve the problem of translating the traditional wood-mould drawing into a numerical model, to set up the solid models of volute, diffuser, wheels, tail pipe. The continuity equation, momentum equation, the Reynolds stress equations and the RANG turbulent k ?εmodel were taken as the governing equations in processing, Established the overall water turbine runner module and the runner module structure in FEM. Using the ALE technique to describe the movement interference in the flow channel, to achieve fluid and solid energy exchange between the fluid and solid at the interface. Fluid-structure interaction analysis by ADINA finite element software format and structure of equations of fluid dispersion, while achieving the runner blades of fluid-structure interaction. The natural frequencies and mode shapes of the runner both in air and in water were calculated, and the comparative analysis were done, moreover, the effects of the viscous fluid characteristics on the dynamic of runner were discussed in detail. And the stress and strain, displacement and torque, flow pressure, velocity, and k ?εdistribution of the steady-state one-way coupling and non-steady double-way coupling rotor blade structure was achieved at the same time. Therefore, fluid runner blade coupling analysis, in-depth understanding of blade vibration mechanism to reduce the crack occurred, to ensure safe and stable operation unit is a great significance.