Influence of Structural Parameters and Flow Conditions on the Dynamic Behaviour of Flexible Labyrinth Seals

摘要

Measurements are presented that show the influence of structural parameters and flow conditions on the dynamic behaviour of flexible labyrinth seals with compressible flow. The objective of the paper is to show that acoustic resonance of the cavity (i.e. frequencies of the coupled system close to acoustic natural frequencies) between the specimens' surface, outside the labyrinth chamber, is of evident importance for structural vibrations of the coupled system. Acoustic modes in the cavity are calculated by means of Finite Element Method (FEM) and the results are compared with measured pressure amplitudes at different positions in the cavity. Measurement data allows identification of acoustic modes and the structures' mode shape using phase angles of sensor signals from different circumferential positions.