QinetiQ helps solve DLE combustor acoustic fatigue and achieves a world first

Citation

(2003), "QinetiQ helps solve DLE combustor acoustic fatigue and achieves a world first", Sensor Review, Vol. 23 No. 1. https://doi.org/10.1108/sr.2003.08723aaf.002

QinetiQ helps solve DLE combustor acoustic fatigue and achieves a world first

QinetiQ helps solve DLE combustor acoustic fatigue and achieves a world first

Keywords: Infrared, Imagine

Achieving another world first, QinetiQ is now successfully measuring dynamic flame response (transfer function) in a practical combustor operating at realistic conditions. This is then being used to help design oscillation-free dry low emission (DLE) combustors and so increase life expectance and improve performance (see Plate 1).

Increasingly stringent emissions legislation has been a key factor for the introduction of DLE combustors as the preferred solution by most gas turbine manufacturers. However, these systems by their nature are inherently prone to structural fatigue and operating instability, due to high amplitude acoustic perturbations.

Plate 1 QinetiQ’s flame speed rig with (inset) the flame as seen through the viewing window

The work was performed by QinetiQ, Europe’s leading science and technology organisation, at its Farnborough headquarters, using a test rig specially designed by the in-house combustion team to measure combustion instability. This has provided critical transfer function information that is now being incorporated into design tools, used for the prediction of oscillation frequency and amplitude values. Until now inducing sufficiently large, variable frequency, pressure perturbations in a cost-effective manner was not possible. QinetiQ solved this problem by using a siren to induce pressure oscillations into the air supply at incremental frequencies and measuring the flame response using light emission at a narrow wavelength.

QinetiQ is now using the rig to help manufacturers to characterise their particular combustor design frequency response under full operating conditions.

For further information, please contact: Douglas Millard, QinetiQ Press, A1 Building, Cody Technology Park, Ively Road, Farnborough, Hants GU14 0LX. Tel: +44 (0) 1252 3946111/145731457212809; E-mail: DMillard@QinetiQ.com; Web site: www.QinetiQ.com