Abstract
Aeroelastic phenomena in the low-pressure compression (LPC) system of civil turbofan engines can cause a significant high-cycle fatigue (HCF) risk to the LPC components. Currently, the mechanical integrity risk to the LPC components is assessed by performing multiple, discrete aeromechanical simulations, which require large resources and incur high time-cost. Therefore, the development of a comprehensive modellingsimulation approach is necessary to assess multiple phenomena and components simultaneously that can provide accurate results within design timescales.
This paper presents the methodology for generating a common, system-level model for investigating multiple aeroelastic phenomena in fan and outlet guide vanes (OGVs). The development of a high fidelity, full-annulus CFD model of the whole low-pressure compression system is described. Time accurate unsteady CFD simulations are then conducted at multiple flight conditions. These information-rich simulations are interrogated to extract various parameters of interest to assess multiple aeroelastic phenomena.
The aeroelastic parameters are used to investigate 1EO fan forced response, fan alternating passage divergence (APD) response, OGV buffet, and OGV resonant forced response etc. In the second part of this paper, the application of this modelling methodology is demonstrated to evaluate and to better understand the efficacy of OGV asymmetric cyclic patterns.