Numerical Predictions and Measurements of Discharge Coefficients in Labyrinth Seals

The present paper illustrates the possibilities and limitations in applying advanced numerical codes for the description of the flow through labyrinth seals to evaluate the discharge coefficient. Comparison with data derived from detailed measurements in a newly developed test facility are reported. Pressure ratios and geometrical parameters are varied in wide ranges, reflecting engine conditions. The two-dimensional, elliptic finite difference code is applied to the compressible, turbulent flow in straight and stepped seals utilizing the standard k-ε-model. Good agreement of the predictions with the measurements is achieved for pressure ratios up to 2.5.