Internal Flow Calculation And Dynamic Characteristics Analysis Of Francis Turbine

With the rapid development of technology, automation degree of unit operation is higher. So there are more remote control hydropower plants without or less people on duty. Then the operation stability of unit is stricter. This article takes long and short blades turbine as example, characteristics of 3D flow field and dynamic characteristics of blade are analyzed comprehensive on consideration of fluid-solid coupling,and then carry out the numerical research of turbine. Main contents are shown as following:First, research and analyze the numerical simulation methods and fluid dynamic models of flow pass, structural statics of runner, numerical simulation methods and dynamic models of rotor, then build mechanical model for blade fluid-solid coupling analysis.Second, research and analyze mathematical model of 3D turbulent computation, especially analyze SST model detailedly. After computational research, SST model is more accurate and credible.It is a excellent model for interial turbulent flow of turbine, especially for turbulent flow shear stress transmission, accurate simulation of near wall, rotary motion, pressure fluctuation of draft tube vortex, and so on.Third, coupling flow field and rotary prestress are considered in dynamic characteristics analysis of rotating machinery runner first time in this paper. And it is found: Modal frequency in same medium has little increased,Modal shape occurs movement of maximum displacement point and change of vibration direction,Constraint is most sensitive for runner frequency. Comparing runner nature frequency and frequency under consideration of rotary prestress, coupled stress field and constraint condition, it has none obvious regularity. But compare the frequency under the same vibration mode, the former is bigger, and more sensitive...