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Place ENS Paris-Saclay, Amphithéâtre Dorothy Hodgkin
Numerical method for the prediction of Variable Stator Vanes bearing's wear
The Variable Stator Vane (VSV) bearings wear in turbojet engine is a significant problem for compressors efficiency and stability requiring adapted models. The VSV bearings are located at the heart of a complex system and contribute to its efficiency and stability by avoiding major incidents of surge and rotor-stator contact. However, the VSV bearings are subjected to a three-dimensional time-varying loading, combining aerodynamic forces and oscillating loading. Current numerical models do not guarantee both reliable results and adequate computation times for pre-sizing in a design office to simulate several hundred hours of flight. This thesis presents a fast and reliable method for predicting the VSV bearings wear, taking into account the complexity of the system geometry and loading. The proposed model is based on a three-dimensional analytical formulation of this highly non-linear wear problem. It is solved by the Newton-Raphson method and developed on Mathematica. Simplifying hypotheses and a semi-analytical estimation of the Jacobian are proposed and significantly reduce the computational time. The three-dimensional evolution of the wear profile of VSV bushings and the resulting contact pressures for entire flight cycles are thus obtained. The developed method is applied to real configurations tested on a new test bench developed at Safran Aircraft Engines.
The jury will be composed of:
Alain DAIDIE - Professor - INSA Toulouse (Reviewer)
David DUREISSEX - Professor - INSA Lyon (Reviewer)
Gaël CHEVALLIER - Professor - FEMTO-ST, Université Bourgogne Franche-Comté (Examiner)
Ida RAOULT - Research engineer - Safran (Examiner)
Nathalie SERRES - Tribology expert - Safran Aircraft Engines (Invited)
Pierre-Alain GUIDAULT - Professor - LMPS, ENS Paris-Saclay (Thesis co-supervisor)
Pierre-Alain BOUCARD - Professor - LMPS, ENS Paris-Saclay (Thesis supervisor)