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|Title: ||Large eddy simulation and PIV measurements of unsteady premixed flames accelerated by obstacles|
|Authors: ||Di Sarli, Valeria|
Di Benedetto, Almerinda
Long, Edward J.
Hargrave, Graham K.
|Keywords: ||Large eddy simulation|
Particle image velocimetry
Sub-grid scale turbulence
|Issue Date: ||2009|
|Publisher: ||© Springer Science+Business Media B.V.|
|Citation: ||DI SARLI, V. ... et al, 2009. Large eddy simulation and PIV measurements of unsteady premixed flames accelerated by obstacles. Flow Turbulence and Combustion, 83 (2), pp.227-250.|
|Abstract: ||In gas explosions, the unsteady coupling of the propagating flame and the flow field induced by
the presence of blockages along the flame path produces vortices of different scales ahead of the
flame front. The resulting flame/vortex interaction intensifies the rate of flame propagation and
the pressure rise.
In this paper, a joint numerical and experimental study of unsteady premixed flame propagation
around three sequential obstacles in a small scale vented explosion chamber is presented. The
modelling work is carried out utilising Large Eddy Simulation (LES). In the experimental work,
previous results [Patel, S.N.D.H., Jarvis, S., Ibrahim, S.S., Hargrave, G.K., Proceedings of the
Combustion Institute 29, 1849-1854 (2002)] are extended to include simultaneous flame and
Particle Image Velocimetry (PIV) measurements of the flow field within the wake of each
Comparisons between LES predictions and experimental data show a satisfactory agreement in
terms of shape of the propagating flame, flame arrival times, spatial profile of the flame speed,
pressure time history and velocity vector fields.
Computations through the validated model are also performed to evaluate the effects of both
large scale and sub-grid scale (sgs) vortices on the flame propagation. The results obtained
demonstrate that the large vortical structures dictate the evolution of the flame in qualitative
terms (shape and structure of the flame, succession of the combustion regimes along the path,
acceleration-deceleration step around each obstacle, pressure time trend). Conversely, the sgs
vortices do not affect the qualitative trends. However, it is essential to model their effects on the
combustion rate to achieve quantitative predictions for the flame speed and the pressure peak.|
|Description: ||The final publication is available at link.springer.com.|
|Version: ||Accepted for publication|
|Publisher Link: ||http://dx.doi.org/10.1007/s10494-008-9198-3|
|Appears in Collections:||Published Articles (Mechanical, Electrical and Manufacturing Engineering)|
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