Dynamic equation and response of turbine runner blade under flow excitation

Abstract

Considering the complex vibration phenomenon of turbine runner blades under the flow excitation, the nonlinear coupling dynamic equation, which contains hydraulic parameters and blade structure parameters, is established by the finite element method, based on geometrical nonlinearity and fluid–structure interaction of runner blades. According to the dynamic equation, the dynamic response of turbine runner blades under the flow excitation is simulated and analyzed through an example and is compared with the experimental results. The research shows that the proposed equation can well reflect the relation between the dynamic performance of turbine runner blades and its hydraulic parameters, structural parameters, and material parameters. Therefore, the equation provides a necessary theoretical basis for further study on deep-seated problems such as the dynamic characteristics of runner blade and the mechanism of vibration fatigue of runner blade.