Ajisafe, A;
Talibi, M;
Ducci, A;
Balachandran, R;
Parsania, N;
Sadasivuni, S;
Bulat, G;
(2019)
Study of dynamical instabilities in Siemens liquid spray injectors using complementary modal decomposition techniques.
In:
ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition.
The American Society of Mechanical Engineers (ASME): Phoenix, AZ, USA.
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Abstract
Liquid fuel spray characterisation is essential for understanding the mechanisms underlying fuel energy release and pollutant formation. Careful selection of operating conditions can promote flow instabilities in the fuel spray which can enhance atomisation and fuel mixing, thereby resulting in more efficient combustion. However, the inherent instabilities present in the spray could have adverse effect on the combustor dynamics. Hence, it is important to better understand the dynamical behaviour of the spray, and particularly at representative operating conditions. This work describes an experimental investigation of dynamical behaviour of pressure-swirl atomisers used in Siemens industrial gas turbine combustors, at a range of chamber pressures and fuel injection pressures, using high speed laser planar imaging. Two modal decomposition techniques — Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) — are applied and compared to assess the spray dynamics. Results indicate that both POD and DMD are able to capture periodic structures occurring in the spray at different spatial length scales. The characteristic frequencies estimated from both the methods are in good agreement with each other. Both techniques are able to identify coherent structures with variable size, shape and level of staggering, which are observed to be dependent on the pressure difference across the atomiser and the chamber pressure. The spatio-temporally resolved data and the results could be used for spray model development and validation. Furthermore, the methods employed could be applied to other fuel atomisers, and more complicated conditions involving cross flow and higher chamber temperatures.
| Type: | Proceedings paper |
|---|---|
| Title: | Study of dynamical instabilities in Siemens liquid spray injectors using complementary modal decomposition techniques |
| Event: | ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition |
| Location: | Phoenix, AZ |
| Dates: | 17 June 2019 - 21 June 2019 |
| ISBN-13: | 978-0-7918-5862-2 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1115/GT2019-91473 |
| Publisher version: | https://doi.org/10.1115/GT2019-91473 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Ejectors, Sprays, Fuels, Pressure, Combustion chambers, Dynamics (Mechanics), Combustion, Cross-flow, Flow instability, Imaging, Industrial gases, Lasers, Model development, Periodic structures, Pollution, Principal component analysis, Shapes, Temperature, Turbines |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10090875 |
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