Influence of honeycomb structures on labyrinth seal aerodynamics

Shroud cavities in aero engines are typically formed by a labyrinth seal between the rotating turbine shroud and stationary casing wall. To mitigate rub-in reduce weight, often features honeycomb structures above rotor fins. In this paper, aerodynamic performance of such is experimentally investigated using test rig featuring both smooth honeycomb-tapered walls. Measurements show that discharge coefficient decreases for configuration while losses subsequent windage heating flow increase. A variation rotational speed reveals additional sensitivities to local field swirl chamber. Numerical simulations conducted validated experiments. good agreement prediction measurements jet via evolution pressure across sealing fins identified. contrast, integral parameters larger deficits. Empirical correlations from available literature satisfactorily predict leakage mass rate if rotation low smooth. High presence honeycombs, however, prove challenging reveal potential further improvements. We propose simple a-posteriori correction can capture effect on accounting changes momentum area.