Leakage Behavior Analysis of Honeycomb Labyrinth Seals through Compared CFD and 1D Analytical Approaches

The present work focuses on non-rotating honeycomb labyrinth seals, devices utilized to improve the efficiency by reducing the leakage flow, in modern Low Pressure Turbines (LPT) on aircraft engines. This research provides an effective comparison among different designs, pointing out how the most influencing geometrical parameters affect the labyrinth seal leakage flow behavior. The first step consists in the validation of a numerical model, based on the literature data, by using the CFD approach. Then, a geometrical sensitivity is carried out, where the effects of combined variations of the seal clearance, the fin tip thickness and the honeycomb cell diameter are evaluated. The CFD analysis provides the detailed flow pattern and leakage flow information. These results are utilized to develop a 1D analytical model, allowing the prediction of the labyrinth seal leakage behavior simply referring on the geometrical data and consequently reducing the computational time and costs.