Investigation on the Effect of Honeycomb to the Leakage of Labyrinth Seal Within Support Seal System

Numerous studies have demonstrated the value of the honeycomb structure for improved seal performance, particularly for reduced leakage. However, the majority of the related simulations are performed with single seal. In order to make better simulation, this paper imported a more realistic flow field model with multiple labyrinth seals extracted from the support seal system in the low-pressure turbine part of a turbofan engine model. First, comparison of analytical and simulation leakage was made. The results of the simulation leakage were in acceptable agreement with the results of the analytical model that accounts for flow coefficient, seal type correction coefficient, and tooth number. Then, simulation for the system with multiple seals was carried out. Less leakage for every seal can be seen. Maximum reduction of leakage is 6.83%. Further, three different honeycomb cell size lands (1.1 mm, 0.8 mm, 0.5 mm) was introduced for isolated seals and support seal system. Maximum reduction of leakage is 20.50% with 0.5 mm honeycomb size. Less leakage from honeycomb configuration can be mainly attributed to flow separation into the honeycomb cells and turbulence kinetic energy dissipation. Analyzing the leakage of the support seal system, one conclusion was drawn, when structure or parameter of one single seal changes, the flow pattern within the whole system can be affected and further have significant impact on the leakage of the entire system.