Combustion dynamics of spray flames

Flame Transfer Functions of a swirling spray flame

While the concept of the Flame Transfer Function (FTF) has been widely applied to gaseous flames, much less work has been done on spray flames. This is mainly because of the high complexity in e.g. measuring droplet velocities or the robust numerical computation of liquid sprays in turbulent reacting flows.

During the KIAI-Project, I was working together with experimentalists from the ONERA in Toulouse. The test rig contained an aeronautical swirling device (triple staged) with a pilot and a multi-point fuel injector for liquid kerosene. Our objective was to correctly reproduce the Flame Transfer Function of the swirling spray flame with LES. The results from the collaboration can be found in the following publication:

A. Ghani, L. Gicquel & T. Poinsot
Acoustic analysis of a liquid fuel swirl combustor using dynamic mode decomposition
ASME Turbo Expo: Turbine Technical Conference and Exposition (2015), pp. 1-9



Transverse combustion instabilities in an aeronautical combustor

One of the most famous examples of transverse modes is the F1-engine of the Saturn V. Back in the 1960’s, more than 1200 full-scale tests with varying injector designs have been performed in order to stabilize the combustion process. Still, transverse modes develop in modern combustion devices and little is known. During my thesis I worked on the numerical simulation of transverse instabilities in order to better understand the physical mechansisms. Here you can watch my numerical simulations of these modes during action for an aeronautical system and an afterburner.

A. Ghani, T. Poinsot, L. Gicquel & J.-D. Müller
LES Study of Transverse Acoustic Instabilities in a Swirled Kerosene/Air Combustion Chamber
Flow, Turbulence and Combustion (2016), vol. 96 (1), pp. 207-226