Numerical Simulation Of Leakage Character Of Aero-Engine Labyrinth Seals

Labyrinth seals are widely used in the seal system of aero-engine inside chamber for they have many merits, such as simple structure, low cost and good sealing effect. They achieve excellent sealing result by dissipating the inside fluid energy. The geometry of labyrinth seal greatly influent its sealing effect. In order to deeper understand the sealing mechanism of labyrinth seal, an in-depth research on the effect of the geometry factors on the sealing effect is made using CFD, the regularity results can be applied in engineering applications.First of all, this paper analyzed relevant literature about leakage of labyrinth seals and sums up the effect condition of different influencing factors on leakage and the comparison result for different kinds of labyrinth seals. Then validation analysis to the grid model and the turbulence model in the numerical simulation of labyrinth gas seals was given. Different typical kinds of labyrinth seals were comparatively analyzed by using CFD, on this basis, the effects of the key geometry factors on leakage of labyrinth seals were argued. In the end, nine kinds of common labyrinth seals of aero-engine were defined as a unified structure model, the effects of structural parameters of labyrinth seal on leakage was studied by numerical study by Taguchi Analysis, the effects of different structural parameters on leakage were qualitative and quantitative analyzed by using intuitionist analysis and square-difference analysis and a comparative analysis of the leakage of nine types aero-engine labyrinth seal was done, the weight of every influencing factor was gained.This paper reveals the basic mechanism of throttling effect, jet effect, eddy effect and breathable effect by using CFD. By studying the impact trend and reason of clearance, tooth width, step height, step distance, space width and angle of inclinationon on labyrinths seals, The results prove that the sealing effect of downstair labyrinths is the best, upstair labyrinths is the second and the straight labyrinths is the worst, the sealing effect of upstream labyrinths is the best, straight labyrinths is the second and the downstream labyrinths is the worst.The test results of orthogonal method show that there’s an incremental impact of clearance and tooth width on leakage of labyrinth seals, the leakage of labyrinth seals get smaller with the increase of the number of teeth and space width, the leakage of labyrinth seals change law lacks in regularity as the height of tooth, included angle and step distance change. The analysis of variance shows the number of teeth, clearance and step height have very appreciable impact on leakage, tooth width and angle of inclination have appreciable impact on leakage, the height of tooth, included angle and step distance impacts turn out to be small. The affection of clearance is more than65%, the affection of the number of teeth is16.5%, the sum affection of step distance, tooth width and angle of inclination is14.3%, and the sum affection of remaining parameters is less than4%. The research results provide a detailed basis and reference for the optimized engineering design of labyrinth seals of aero-engine.