Session: 36-04 UQ & Sensitivity Analysis - Part 1

Submission Number: 174880

Uncertainty Quantification and Robustness Enhancement of Aero-Engine Pre-Swirl Systems Based on Polynomial Chaos Expansion 

Uncertainties in seal tooth clearances of the pre-swirl system exert a significant influence on the cooling performance of aero-engine secondary air systems, and their effects cannot be neglected in practical operation. To address this issue, the present study employs the Polynomial Chaos Expansion (PCE) method to systematically quantify and analyze the influence of clearance variations on system performance. Both inner and outer seal clearances are modeled as uncertain geometric parameters, and their impacts on the temperature-drop characteristics of the system are evaluated under fixed boundary conditions.

The results demonstrate that the inner seal clearance is the dominant source of uncertainty. Specifically, under take-off conditions, when the standard deviation of the inner clearance reaches 40% of its cold-state value, the standard deviation of the temperature drop increases to 7.9 K. Such findings highlight the critical importance of controlling geometric accuracy during assembly and engine operation to ensure reliable cooling performance.

To mitigate the adverse effects of clearance deviations, two improvement strategies are investigated. The first approach, increasing the inlet swirl ratio at the inner seal, effectively reduces the coefficient of variation of the temperature drop by 24.2% without altering its mean value. The second approach, adopting an inverted-tooth configuration, diminishes the sensitivity of inlet mass flow to clearance variations. Under identical input deviations, this design reduces the coefficient of variation of inlet mass flow by 31.2%, enhances the mean temperature drop by 12.9%, and decreases its variability by 45.2%.

Overall, this study not only reveals the mechanisms through which clearance uncertainties affect the pre-swirl system but also provides practical design guidelines. The proposed strategies offer valuable insights for improving the robustness and reliability of cooling air delivery in aero-engine secondary air systems.

Presenting Author: Tengyue Guo Research Institute of Aero-Engine, Beihang University

Presenting Author Biography: Tengyue Guo, graduate student from School of Energy Science and Engineering, Central South University, Hunan, China, since 2020. He is from the group of Aeroengine Complex Systems Safety and Airworthiness. His research interests include uncertainty analysis and stability design of air system.

Authors:

Tengyue Guo Research Institute of Aero-Engine, Beihang University
Peng Liu Research Institute of Aero-Engine, Beihang University
Chuankai Liu Research Institute of Aero-Engine, Beihang University
Tian Qiu Research Institute of Aero-Engine, Beihang University