Session: 03-01 Hydrogen Combustion

Paper Number: 101960

101960 - Assessment of the Dynamical Behaviour of Hydrogen Combustors With Recurrence Quantification Analysis (Rqa) 

Hydrogen has immense potential as a future energy vector for power and propulsion applications, but there are several challenges, including flame stability, flashback and emissions, that impede its widespread use in modern energy systems. Hydrogen systems are required to be operated at fuel-lean conditions to avoid high NOx emissions and flashback issues, however lean operation makes systems more susceptible to thermoacoustic instabilities and lean blow-off (LBO). Understanding these dynamical behaviours is key to develop robust operational strategies.

Recurrence Quantification Analysis (RQA) is an effective tool to study nonlinear dynamics, and has been applied in this study to characterise hydrogen flame behaviour in industry-relevant laboratory-scale combustion systems. RQA was demonstrated on two different configurations – hydrogen lean direct injection (LDI) combustor and a radial swirl combustor operated on methane-hydrogen blends. RQA was carried out on time-resolved data of (i) pressure measurements in the combustor and (ii) integrated OH* chemiluminescence signals. These commonly used measurements were selected to develop a tool which can be applied easily to other industrial systems.

The bulk velocity and global equivalence ratio were varied, and two quantifiable parameters, Shannon entropy and recurrence rate, were extracted from the RQA, which allowed determination of different dynamical behaviours – blow-off, stable, intermittent, and limit-cycle.  High values of both parameters indicated conditions near blow-off, while low values were an indication of limit cycle oscillations. The outcome of this work will allow development of efficient predictive tools for nonlinear data analysis using reduced number of inputs.

Presenting Author: Andrea Ducci University College London

Presenting Author Biography: Andrea Ducci is an Associate Professor in the Mechanical Engineering Department at University College London, and his expertise is in experimental flow, mixing and spray dynamics. He obtained his PhD at King’s College London where he was awarded a five years EPSRC Advanced Research Fellowship to further expand his knowledge in Laser diagnostics (PIV, PDPA, LDA, GSV) and develop advanced post processing tools based on modal decomposition and Lagrangian coherent structure analysis.

He has investigated a broad range of flows, both of fundamental, i.e. vortex ring, cylinder wake and grid generated turbulence flows, and of industrial relevance, i.e. fuel sprays, acoustically excited flames. His research interests also include exploring the viability of alternative fuels for Energy applications.

He is a an active member of the P-Lab at UCL and is currently collaborating with major international industrial partners such as Siemens Energy, Mitsubishi Power and Reactor Engines.

Authors:

Ali Alshahrani University College London
Midhat Talibi University College London
Chinonso Ezenwajiaku University College London
Jadeed Beita Siemens Energy Industrial Turbomachinery Ltd.
Mark Picciani Reaction Engines Ltd.
Ramanarayanan Balachandran University College London
Andrea Ducci University College London