Analysis Of Aero Engine Labyrinth Seal Characteristics Based On Maintenance Data

Labyrinth seal is a kind of long life and effective non-contact sealing device widely used in the aero-engine.The labyrinth structure is to limit the leakage of the fluid by increasing the flow resistance by the inrush and sudden expansion of the channel.The sealing effect of the labyrinth seal has an important influence on the performance of the engine.If the labyrinth is worn and corroded at work,the sealing efficiency will change with the pressure,and the performance of the engine will be affected.It is of great significance to study the sealing characteristics of the labyrinth teeth.Firstly,the related literatures on labyrinth seal characteristics at home and abroad were studied.The influence of different factors on the sealing characteristics of labyrinth were analyzed.Secondly,the main seal devices of several typical aero-engines,CFM56,V2500 and LEAP,are analyzed,and the characteristics and application of different labyrinth structures are explored.The sealing schemes for three types of turbofan engines in mainstream roads are studied.The clearance value of the main sealing device in the main airflow of the engine was studied,and the effect of different positions on the performance of the engine was investigated by using three different methods of correlation analysis.Finally,the sealing mechanism of the labyrinth teeth is thoroughly understood by the method of numerical simulation,and the influence of different factors on the sealing characteristics of the labyrinth teeth is studied.The standard of sealing effect of labyrinth is measured by leakage and leakage coefficient.The influence of the initial inlet total pressure on the sealing performance is explored,and the influence of the number of teeth,the gap between the teeth,the width of the tooth tip and the front angle on the sealing characteristics of the labyrinth seal is analyzed.At the same time,in the labyrinth seal structure of two teeth and three teeth,different front tilt angles are arranged respectively,then a new type of combined labyrinth seal structure is formed.Their sealing performance is explored.In the two teeth and three teeth labyrinth,the structure of the first teeth with angle has a lower leakage,and better sealing performance.Combination type labyrinth seal changes the material flow thought changing the type of teeth structure.It makes more energy dissipation and low leakage in the cavity.The sealing characteristics of the combined labyrinth seal structure are better than that of the straight-through labyrinth sealing structure with single angle.The combined labyrinth sealing structure can be a new development direction to meet the new requirements of aero-engine sealing technology.