Analysis Of Brush Seals Flow Heat Transfer And Bristles Motion Status

Brush seals as an advanced flexible contact dynamic seal,which is the key component of aero engine.With the development of aero engine to high parameters,brush seals bristles in the high-pressure airflow and rotor bounce coupling effects,bristles will produce contact deformation,bristles generate frictional heat at high speed of the rotor,which seriously affects the sealing performance and service life of brush seal.Therefore,it is great theoretical significance and practical engineering application value to research on the flow heat transfer and bristles motion status of brush seals.In this paper,the flow heat transfer of brush seals and the state of bristles motion status were studied from the theoretical,numerical and experimental aspects.In theory aspect,the theory model of brush seals porous medium model,the three-dimensional steady state theory model and the three dimensional transient fluid-structure interaction theory model were established respectively.The ALE(Arbitrary Lagrange-Euler)fluid-structure interaction method of brush seals was proposed.In numerical aspect,a three-dimensional steady-state flow heat transfer solution model and a solution model based on ALE three dimensional transient fluid-structure interaction were established.In the experimental aspect,the observable bristles motion status deformation trajectory experimental device were designed and built.The leakage characteristics and the state of bristles movement of brush seals were studied.The study results show that,the solution model based on ALE fluid-structure interaction of brush seals.It resolves the traditional brush seal fluid-structure interaction solution model is difficult to calculate because of mesh distortion caused by the deformation contact of bristles.It can accurate calculation flow field and mechanical characteristics of brush seals.Maximum pressure drop occurs at the end stage of multi-stage brush seals.Bristles temperature increases stage by stage,with the pressure ratios,speed,interference,and heat flux increases the maximum temperature increases.The maximum deformation of bristles appears on the free end position of the bristles.The fixed position of the bristles has the maximun stress.Brush seals leakage decreases gradually with the increasing number of bristles row.With the increasing of the clearance of brush wire,the height of backing plate fence,the leakage rises firstly and then reaches a stable value.Bristles blow down and bristles disturbance mainly occurs in the highpressure area.The research results of this paper provide a theoretical basis for the optimization design of brush seals structure.