Numerical analysis of the dynamic flame response of a spray flame for aero-engine applications

Abstract

Incoming standards on NO x emissions are motivating many aero-engine manufacturers to adopt the lean burn combustion concept. One of the most critical issues affecting this kind of technology is the occurrence of thermo-acoustic instabilities that may compromise combustor life and integrity. Therefore the prediction of the thermo-acoustic behaviour of the system becomes of primary importance. In this paper, the complex interaction between the system acoustics and a turbulent spray flame for aero-engine applications is numerically studied. The dynamic flame response is computed exploiting reactive URANS simulations and system identification techniques. Great attention has been devoted to the impact of liquid fuel evolution and droplet dynamics. For this purpose, the GE Avio PERM (partially evaporating and rapid mixing) lean injection system has been analysed, focussing attention on the effect of several modelling parameters on the combustion and on the predicted flame response. A frequency analysis has also been set up and exploited to obtain even more insight on the dynamic flame response of the spray flame. The application is one of the few in the literature where the dynamic flame response of spray flames is numerically investigated, providing a description in terms of flame transfer function and detailed information on the physical phenomena.

Model-Based Approach for Combustion Monitoring Using Real-Time Chemical Reactor Network

“…Da nonuniformity can also lead to the onset of flow instabilities resulting in LBO [9]. Experimental and numerical studies have investigated species distribution in different combustor geometries, injector designs and fuel compositions e.g., [10][11][12][13][14][15][16][17]. Lean flame blowout modeling for an aeroengine application using zonal modeling was reported in [18][19][20].…”

Flame response of solid propellant AP/Al/HTPB to a longitudinal acoustic wave

“…19 In contrast, the interaction between thermo-acoustic oscillations and liquid fuel sprays has been the subject of many theoretical and experimental studies. [20][21][22][23] These investigations also include the work of Yang and Anderson 24 and Harrje and Reardon 25 on combustion instabilities in a liquid rocket engine.…”