Thermomechanical Model Reduction for Efficient Simulations of Rotor-Stator Contact Interaction

Abstract

Turbomachinery rotor-stator unilateral contact induced interactions play a growing role in lifecycle analysis and thus motivate the use of accurate numerical prediction tools. Recent literature confirmed by ongoing in-house experiments have shown the importance of thermomechanical coupling effects in such interactions. However, most available (possibly reduced-order) models are restricted to the sole mechanical aspects. This work describes a reduction technique of thermomechanical models involving unilateral contact and frictional contact occurrences between rotor and stator components. The proposed methodology is grounded on Guyan and Craig–Bampton methods for the reduction of the structural dynamics in conjunction with Krylov subspace techniques, and specifically the Craig–Hale approach, for the reduction of the thermal equations. The method has the capability to drastically reduce the size of the model while preserving accuracy. It stands as a reliable strategy to perform simulations of thermomechanical models with localized mechanical and thermal loads.

Multi-physics numerical simulation of an experimentally predicted rubbing event in aircraft engines

“…The resulting thermal load on the casing may have a twofold effect: (1) locally, as impacted areas are heated, thermal expansions may reduce blade/casing clearances and (2) globally, the heating of the casing may yield its distortion and thus modify blade/casing clearances at any angular location depending on the casing mounting points. Thermomechanics on the rotor [31,32] is not considered in this study as there is no experimental evidence that very localized heated areas-along the blade tip-may significantly impact its dynamics.…”