Study on FSI Analysis Method of a Large Hydropower House and Its Vortex‐Induced Vibration Regularities

Abstract

The working principle of a large hydropower station is to guide the high-pressure water flow to impact the turbine to rotate and generate electricity. The high-pressure water flow impacts the turbine blades, which forms complex high-speed eddy currents in the spiral case and the draft tube and causes complicated vortex-induced vibration problems. Traditionally used harmonic response methods and dynamic time-history analysis methods are difficult to reflect this complex fluid-solid dynamic coupling problem. In this paper, the bidirectional fluid-structure interaction (FSI) simulation analysis theory for a large hydropower house is studied, and the analysis methods of geometric simulation, mechanical simulation, and vibration energy transmission path simulation are presented. A large-scale 3D fluid-hydraulic machinery-concrete structure coupled model of a hydropower house is established to study the vortex-induced vibration mechanism and coupled vibration law during transient unit operation. A comparison of the fluid results against the in-site data shows good agreement. Structural responses of vibration displacement, velocity, and acceleration reveal coupled regularity of hydraulic machinery-concrete structure-fluid during blades rotating periods, and it comes to the conclusion that the turbine blade rotation is the main vibration source of the hydropower house. The research results can provide a scientific basis for the design and safe operation of the hydropower house.

A Review of the Recent Research on Hydraulic Excitation-induced Vibration in Hydropower Plants

“…Some scholars have used the FSC method to analyse the effect of hydraulic excitation force on powerhouse vibration. Zhang et al [49] analysed the vortex excitation mechanism and HEIV law during transient operation of large HP unit. The pressure fluctuations in typical locations were validated by using field measurement data and compared with the calculation results to ensure that the numerical calculation results can represent the vortex characteristics and pressure fluctuations in the flow field.…”

A High-performance Open-source Solution for Multiphase Fluid-Structure Interaction

“…In the present FSI framework, the consistency of the displacement is implemented, which is not as tight as the consistency of normal velocity, but is easier to implement. It is worth noting that employing consistency of the displacement as the kinematic condition has been validated and applied within numerous FSI studies (Slyngstad, 2017;Tao et al, 2018;Zhang et al, 2020). The fluid forces, or tractions, acting on the fluid-structure interface have to follow the dynamic condition (Slyngstad, 2017;Tuković et al, 2018):…”