Dispersion of entropy perturbations transporting through an industrial gas turbine combustor
File(s)
Published version
Author(s)
Xia, Y
Duran, I
Morgans, AS
Han, X
Type
Journal Article
Abstract
In the context of combustion noise and combustion instabilities, the transport of entropy perturbations through highly simplified turbulent flows has received much recent attention. This work performs the first systematic study into the transport of entropy perturbations through a realistic gas turbine combustor flow-field, exhibiting large-scale hydrodynamic flow features in the form of swirl, separation, recirculation zones and vortex cores, these being ubiquitous in real combustor flows. The reacting flow-field is simulated using low Mach number large eddy simulations, with simulations validated by comparison to available experimental data. A generic artificial entropy source, impulsive in time and spatially localized at the flame-front location, is injected. The conservation equation describing entropy transport is simulated, superimposed on the underlying flow-field simulation. It is found that the transport of entropy perturbations is dominated by advection, with both thermal diffusion and viscous production being negligible. It is furthermore found that both the mean flow-field and the large-scale unsteady flow features contribute significantly to advective dispersion — neither can be neglected. The time-variation of entropy perturbation amplitude at combustor exit is well-modelled by a Gaussian profile, whose dispersion exceeds that corresponding to a fully-developed pipe mean flow profile roughly by a factor of three. Finally, despite the attenuation in entropy perturbation amplitude caused by advective dispersion, sufficient entropy perturbation strength is likely to remain at combustor exit for entropy noise to make a meaningful contribution at low frequencies.
Date Issued
2017-09-21
Date Acceptance
2017-09-10
Citation
Flow, Turbulence and Combustion, 2017, 100 (2), pp.481-502
ISSN
1386-6184
Publisher
Springer Verlag
Start Page
481
End Page
502
Journal / Book Title
Flow, Turbulence and Combustion
Volume
100
Issue
2
Copyright Statement
© The Author(s) 2017. Open Access: This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Sponsor
Commission of the European Communities
Ghenadie Bulat
Siemens Industrial Turbomachinery Ltd
Grant Number
FP7 - 305410
Siemens Industrial Turbomachinery
See further info
Subjects
09 Engineering
Mechanical Engineering & Transports
Fluids & Plasmas
Publication Status
Published