Incompressible flow in a labyrinth seal

Abstract

The incompressible flow in a labyrinth seal is computed using the ‘κ−ε’ turbulence model with a pressure-velocity computer code in order to explain leakage phenomena against the mean pressure gradient. The flow is axisymmetric between a rotating shaft and an enclosing cylinder at rest. The main stream in circumferential direction induces a secondary mean flow vortex pattern inside annular cavities on the surface of the shaft. The domain of interest is one such cavity of an enlarged model of a labyrinth seal, where the finite difference result of a computer program is compared with measurements obtained by a back-scattering laser-Doppler anemometer at a cavity Reynolds number of ∼ 3 × 104and a Taylor number of ∼ 1·2 × 104. The turbulent kinetic energy and the turbulence dissipation rate are verified experimentally for a comparison with the result of the turbulence model.