Session: 14-05 Labyrinth Seals

Paper Number: 122314

122314 - Numerical Investigation on the Robustness Assessment and Enhancement of Labyrinth Seal With Axial Displacement and Clearance Deviation 

The labyrinth is widely used in aero-engine, which experience axial displacement and radial deformation during operation due to the interaction of mechanical, aerodynamic, and thermal loads. The axial displacement and radial clearance directly affect the working condition of the labyrinth, and then affect the various functions of the secondary air system. However, in the present research, few researchers have studied the influence of the change of the axial displacement and radial clearance of the labyrinth on the working condition of the labyrinth and the function of the secondary air system in the operation process, as well as devoted to improving the robustness of the sealing performance of the labyrinth to the deviation of the axial displacement and the deviation of the sealing clearance. To evaluate the effect of axial displacement and seal clearance changes on the labyrinth condition and secondary air system function during operation, this paper developed a low-dimensional simulation method of axial displacement and radial deformation under the joint action of mechanical load, aerodynamic load, and thermal load, based on the self-programmed aircraft engine performance and coupled secondary air system analysis model, and combined with the theory of thermoelastic mechanics and data scaling technology. To improve the robustness of the labyrinth to axial displacement and clearance deviations during operation, this study takes inspiration from the interaction between aerodynamic force, axial displacement, and clearance. A new negative feedback labyrinth structure is proposed and the effect of its structural parameters on the flow characteristics is analyzed. Finally, a low-dimensional numerical simulation study was conducted on the negative feedback and traditional stepped labyrinths by integrating the engine primary air system and secondary air systems coupling analysis models. The results show that the negative-feedback stepped labyrinth effectively decreases the sensitivity of its mass flow rate to clearance variation without compromising the sealing performance. Furthermore, the labyrinth has a larger stable working area in both axial and radial directions, reducing the risk of rub-impact during operation and improving the safety and reliability of aeroengine.

Presenting Author: Xin Jin Beihang University

Presenting Author Biography: Xin Jin, graduate student from Research Institute of Aero-Engine, Beihang University, Beijing, China, since 2020. He is from the group of Aeroengine Complex Systems Safety and Airworthiness. His research interests include the probabilistic analysis and robust optimization of secondary air system.

Authors:

Xin Jin Beihang University
Chuankai Liu Beihang University
Peng Liu Beihang University
Zijun Li Beihang University
Shuiting Ding Beihang University