Description du projet
Des modèles améliorés pour mieux maitriser les vibrations des moteurs aérospatiaux
Les toutes dernières conceptions d’aéromoteurs avancés visent une efficience considérablement améliorée afin de contribuer à la réduction de la consommation de carburant et des émissions nocives. Ces modèles sont susceptibles d’augmenter les vibrations à haute fréquence en raison de modifications de facteurs tels que l’écoulement d’air ou le diamètre du turboréacteur. Comprendre l’impact de la propagation de ces vibrations sur l’aéromoteur et sur l’avion en lui-même est crucial pour concevoir des éléments performants et sûrs. Les analyses conventionnelles d’éléments finis se trouvent confrontées à des limitations et l’analyse statistique énergétique (SEA), bien plus adaptée, fait face à des défis nécessitant une compréhension totale de la structure à étudier. Le projet VibSEA, financé par l’UE, comblera ces lacunes grâce à une vaste campagne expérimentale visant à collecter des données et à élaborer un modèle SEA, qui sera ensuite validé en vue de son utilisation dans de futures conceptions.
Objectif
Designed to achieve reduction in fuel consumption, the Ultra-High Bypass and High Propulsive Efficiency Geared Turbofan engine incorporates evolutions likely to produce high frequency (HF) vibration excitations which propagate through the structure. Numerical simulation is an efficient tool to control vibrations hence supporting the mechanical design. Where Finite Element (FE) based approaches show limitations due to computational hardware performances and HF dispersion management, Statistical Energy Analysis (SEA) stand as proven and effective method for this frequency range to predict the vibrational energy transfers across partitions – subsystems – of a structure. Challenges of SEA modelling consist of the structure partitioning which usually requires expertise and the accuracy loss at lower frequencies where the high stiffness of parts or complexity of junctions counter the method initial assumptions. Those statements depend strongly on the studied structure, therefore the objective of the proposed project is to develop and demonstrate a SEA modelling process to predict the vibration propagated in a typical complex engine frame. In this scope, best modelling practices from detailed numerical analysis are engaged to both support an extensive test campaign preparation including test vehicle design and manufacture, and produce models covering the target frequency range: from 400Hz to 10kHz. A crucial phase consists in the validation and update of these models from tests post-processing techniques and known methods such as Experimental SEA, Decay Rate damping estimation or input conductance as well as innovative inverse approaches relying on optimization loops. From the comprehensive comparison of these different methods with tests results, a best methods and associated modelling practices are delivered to the topic leader. CETIM and ESI join their complementary competences to develop the modelling and experimental know how applied to the HF vibrations assessment.
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RIA - Research and Innovation actionCoordinateur
60304 Senlis Cedex
France