Simulating the Metering Characteristics of Labyrinth Seals with the Smooth Shaft

Abstract

The data of analytical and physical simulation of labyrinth seals have been given. The analytical investigation was carried out using the experimental design theory and mathematical model identification theory and the physical investigation was carried out using the unified experimental test rig developed for this purpose. The influence of operating and some geometric parameters, in particular sealed pressure fall, shaft rotation speed, radial clearance, etc. on the operation of labyrinth seals has been studied in many ways. The importance of the influence of tested parameters on the metering characteristics of seals has been described. A mathematical model was proposed for the conventional flow coefficient of the seal based on the representation of the hydraulic resistance of labyrinth seal as a sum of form losses described by analytical expressions taking into consideration physical processes. The model identification problem was solved using the experimental data. The constructed model is used for the range of geometric and operating parameters used for experiments. A technique used for the calculation of the value of gas leakage through the labyrinth seal was improved using the semitransparent mathematical model of conventional flow coefficient for the seal with the smooth shaft that takes into account geometric and operating parameters (D, s, t, h, p 1 /p 2 , n, D).