Research On Seals Of Turbomachinery And Interaction Effect Between Seals And Rotor

For turbomachinery, working medium leaks from the clearance between rotating andstationary components. This part of the working medium that did not pass main flow has nocontribution for work. Therefore, rotor seal is used to packing off the clearance in order toreduce leakage and power loss. Performance improvement causing by excellent seals hasactually reflected in efficiency improvement, operation and maintenance cost reduction, etc.With increasing operating speed and load of rotor (except the generator set), theinteraction of rotor and seals is only growing stronger. If the match between rotor and seal isunsuitable, the consequence is unimaginable. Just under such a background, the author hasproposed to research the interaction of rotor and seals, and discuss rotor vibration rule and FSImethod in deep in this dissertation.Two aspects of research work are completed in this paper: Obtain seal characteristic onleakage and dynamics by numerical analysis of finger seal and its modified structure usingtwo way FSI method; Research motion law of corresponding rotor based on rotor dynamicscalculation, and introduce rotor motion to the flow field analysis of annular rotor seals, thenobtain interactional rule between rotor motion and seals. Summary to say, surrounding theabove problems of the specific research contents includes that:1. Researched flow and non-dynamic characteristics of finger seal thoroughly.(1) The author adopted and improved existing finger seal structures, and obtained thedeformation characteristics of different structures under aerodynamic force by using theoryand numerical analysis quantificationally and qualitatively. The author designed groovedstructures on lift pad and put them into numerical computation, then obtained the specialeffect on lift force and flow of grooved structures, and confirmed the contribution toperformance improvement of finger seal causing by grooved structures.(2) The author has built the complete cycle computation model of finger seal. Bynumerical computation, I have acquired the deformation and flow rules of finger seal, andacquired the effect on performance improvement of finger seal causing by grooved structuresfurther. I have compared the computational results and fashioned test data, and found thesuitable working range in numerical computation that can matching with the test results. The research indicates that groove structure can improve lifting character of finger seal.This research provides an evidence to improve performance or reduce inherent defect offinger seal by simple structural improvement. Deformation and leakage charactersacquired by theoretical and numerical analysis have certain importance to structure design offinger seal.2. Carried out researches on rotor dynamics of sealing rotor and interaction betweenrotor and labyrinth and honeycomb seals.(1) Compiled program to solve vibration parameters by use the method in view of rotordynamics. The author obtained amplitude and frequency of vibration, parameters that candescribe rotor vibration law.(2) The author introduced vibration parameters to unsteady CFD computation of rotorseals, and obtained dynamically characters of labyrinth and honeycomb seals in vibrationcondition. The author analyzed effect on rotor of unbalance aerodynamic force causing byvibration.(3) The author compared difference on leakage character of labyrinth and honeycombseals with different structures, and analyzed the reason of that difference starting from thesource of flow.The results indicated the effect on seal leakage of rotor vibration, and expounded that theaerodynamic force of labyrinth and honeycomb seals can make contribution to reduce rotorvibration. The author also analyzed the superiority on vibration and noise reduction ofhoneycomb seal in the point of view on aerodynamic force.