Detection of discontinuities in nonlinear responses according to different numerical parameters in the context of blade-casing interactions - DUMAS - Dépôt Universitaire de Mémoires Après Soutenance Access content directly
Master Thesis Year : 2021

Detection of discontinuities in nonlinear responses according to different numerical parameters in the context of blade-casing interactions

Détection de failles dans la réponse non-linéaire de systèmes mécaniques, application au contact aube/carter dans les moteurs d'avion

Abstract

The drive towards reducing aircraft engines' aerodynamic losses has led engineers to reduce the clearances between blade tips and their surrounding casing, thereby increasing the risk of blade/casing contact interactions. Tools to accurately predict subsequent nonlinear dynamics are thus essential at design stage. Design of Experiments and the construction of surrogate models are very effective in studying complex and costly experimental blade/casing devices. Nonetheless, the convergence of surrogate models is linked to the smoothness of the response, evidencing the requirement of new approximation approaches for discontinuous responses. In this context, this report proposes a methodology to localize discontinuities in a 2D Design of Experiments inputs space in order to apply approximation methods on the smooth subdomains subsequently. First, a mesh is constructed on the inputs parameter space using a Delaunay triangulation and gradient-based indicators along with polynomial annihilation are then used as refinement indicators. The proposed methodology makes use of the Support Vector Machine to create a smooth approximation of the discontinuity location. Local improvement of the solution is finally completed. The applicability and the robustness of the proposed discontinuity localization tool are then tested on a variety of analytical models. The test cases have demonstrated satisfactory localization of closed discontinuities, multiple discontinuities in the same model, and discontinuities running partially through the domain. The numerically costly engineering model of blade/casing contact interactions is then considered and the proposed methodology is used to localize a jump in the response.
Fichier principal
Vignette du fichier
2021_denis.pdf (8.73 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

dumas-03258195 , version 1 (11-06-2021)

Identifiers

  • HAL Id : dumas-03258195 , version 1

Cite

Sophie Denis. Detection of discontinuities in nonlinear responses according to different numerical parameters in the context of blade-casing interactions. Mechanical engineering [physics.class-ph]. 2021. ⟨dumas-03258195⟩
75 View
48 Download

Share

Gmail Facebook X LinkedIn More