Dry And Wet Modal Test Exploration To The Impeller Of Nuclear Reactor Coolant Pump

The modal calculations of main pump hydraulic parts is of great significance for safety and reliability of nuclear main pump structure.Accurately calculate the natural frequency of the main pump is the premise and foundation of nuclear main pump reliability analysis.Nuclear main pump impeller natural frequencies calculated in dry and wet mode. Nuclear main pump operates in a loop reactor,impeller long submerged in coolant,with revolving machineries like air compressor,steam turbine and so on the difference is,the quality of the attached glue water have the obvious influence to the water frame dynamics characteristic,because incompressible fluid have obvious influence to mass matrix of structure,therefore the quality of attached glue water have extremely important to the nuclear host pump natural frequency influence. It’s about accurate calculation of nuclear main pump impeller in the working status of the critical speed, and other important parameters"Wet-modal" major concern for the vibration characteristics of the structure of the additional fluid effects, as well as a structure of the solid structure of fluid, is a two-way fluid-structure interaction problems due to vibration of the fluid will lead to volatile solids around, it is acoustic coupling problem.In this paper,nuclear main pump impeller in the dry and wet state of modal analysis and transient response analysis by using method of combining the finite element analysis and experiment.Modal analysis can be studied natural frequencies and mode shapes,and other related information. While the transient response can be on the impeller node of the amplitude.Through the modal experiment analysis comprehensively reflect the modal characteristics of the impeller,lay a good foundation and provide useful guidance for the next in-depth study of nuclear main pump reliability design, strength check impeller.