Comparative Analysis of Helically Grooved and Circumferentially Grooved Labyrinth Seal

摘要

Labyrinth seals are used in turbo-machinery for reducing the leakage of working fluid. Theenergy lost by the fluid passing through the gap between labyrinth seal and rotor causes the reduction inleakage rate. But the fluid in between the labyrinth seal and rotor induce various forces (radial andtangential forces). These forces can be represented by certain numbers of coefficients, such as stiffnessand damping coefficients. In this work, a comparative analysis has been carried out between a helicallygroovedand a circumferentially-grooved labyrinth seal using a CFD program Fluent. Parameters such asfluid forces, leakage and rotordynamic coefficients for both the labyrinth seals are calculated. Modellingand analysis have been performed with seal-rotor configurations having different eccentricity ratios (0.1,0.2, 0.34, 0.4, 0.5 and 0.68). Leakage and rotordynamic coefficients have been calculated and comparedfor the two seals under different inlet pressures, rotor speed, etc. The calculated leakage was same forboth the labyrinth seals, but the calculated rotordynamic coefficients were different.