Erratum to: Geometrical Properties and Turbulent Flame Speed Measurements in Stationary Premixed V-flames Using Direct Numerical Simulation

Boundary layer flashback from the combustion chamber into the premixing section is a threat associated with the premixed combustion of hydrogen-containing fuels in gas turbines. In this study, the effect of pressure on the confined flashback behaviour of hydrogen-air flames was investigated numerically. This was done by means of large eddy simulations with finite rate chemistry as well as detailed chemical kinetics and diffusion models at pressures between 0 . 5 and 3 . It was found that the flashback propensity increases with increasing pressure. The separation zone size and the turbulent flame speed at flashback conditions decrease with increasing pressure, which decreases flashback propensity. At the same time the quenching distance decreases with increasing pressure, which increases flashback propensity. It is not possible to predict the occurrence of boundary layer flashback based on the turbulent flame speed or the ratio of separation zone size to quenching distance alone. Instead the interaction of all effects has to be accounted for when modelling boundary layer flashback. It was further found that the pressure rise ahead of the flame cannot be approximated by one-dimensional analyses and that the assumptions of the boundary layer theory are not satisfied during confined boundary layer flashback.

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Experimental study of laminar and turbulent flame speed of a spherical flame in a fan-stirred closed vessel for hydrogen safety application

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2016.07.007 ◽

2017 ◽

Vol 312 ◽

pp. 214-227 ◽

Cited By ~ 14

Author(s):

J. Goulier ◽

N. Chaumeix ◽

F. Halter ◽

N. Meynet ◽

A. Bentaïb

Keyword(s):

Experimental Study ◽

Turbulent Flame ◽

Flame Speed ◽

Closed Vessel ◽

Spherical Flame ◽

Turbulent Flame Speed ◽

Safety Application ◽

Hydrogen Safety

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The effect of oxygen content on the turbulent flame speed of ammonia/oxygen/nitrogen expanding flames under elevated pressures

Combustion and Flame ◽

10.1016/j.combustflame.2021.111521 ◽

2021 ◽

Vol 232 ◽

pp. 111521

Author(s):

Shixing Wang ◽

Ayman M. Elbaz ◽

Zhihua Wang ◽

William L. Roberts

Keyword(s):

Oxygen Content ◽

Turbulent Flame ◽

Flame Speed ◽

Turbulent Flame Speed ◽

Elevated Pressures ◽

Effect Of Oxygen

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Application of a New Turbulent Flame Speed Combustion Model on Burn Rate Simulation of Spark Ignition Engines

10.4271/2016-01-0588 ◽

2016 ◽

Cited By ~ 3

Author(s):

Shiyou Yang ◽

Hemanth Kolla ◽

Nedunchezhian Swaminathan

Keyword(s):

Turbulent Flame ◽

Spark Ignition ◽

Flame Speed ◽

Combustion Model ◽

Spark Ignition Engines ◽

Turbulent Flame Speed ◽

Burn Rate

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Extension of the turbulent flame speed closure model to ignition in multiphase flows

Combustion and Flame ◽

10.1016/j.combustflame.2012.10.006 ◽

2013 ◽

Vol 160 (2) ◽

pp. 351-365 ◽

Cited By ~ 5

Author(s):

Jan M. Boyde ◽

Patrick C. Le Clercq ◽

Massimiliano Di Domenico ◽

Manfred Aigner

Keyword(s):

Multiphase Flows ◽

Turbulent Flame ◽

Flame Speed ◽

Closure Model ◽

Turbulent Flame Speed

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Flame Characteristics and Turbulent Flame Speeds of Turbulent, High-Pressure, Lean Premixed Methane/Air Flames

Volume 2: Turbo Expo 2005 ◽

10.1115/gt2005-68565 ◽

2005 ◽

Cited By ~ 9

Author(s):

P. Griebel ◽

R. Bombach ◽

A. Inauen ◽

R. Scha¨ren ◽

S. Schenker ◽

...

Keyword(s):

Flame Front ◽

Gas Turbines ◽

Equivalence Ratio ◽

Turbulent Flame ◽

Flame Speed ◽

Operating Conditions ◽

Turbulent Flame Speed ◽

Front Position ◽

Preheating Temperature ◽

Lean Premixed

The present experimental study focuses on flame characteristics and turbulent flame speeds of lean premixed flames typical for stationary gas turbines. Measurements were performed in a generic combustor at a preheating temperature of 673 K, pressures up to 14.4 bars (absolute), a bulk velocity of 40 m/s, and an equivalence ratio in the range of 0.43–0.56. Turbulence intensities and integral length scales were measured in an isothermal flow field with Particle Image Velocimetry (PIV). The turbulence intensity (u′) and the integral length scale (LT) at the combustor inlet were varied using turbulence grids with different blockage ratios and different hole diameters. The position, shape, and fluctuation of the flame front were characterized by a statistical analysis of Planar Laser Induced Fluorescence images of the OH radical (OH-PLIF). Turbulent flame speeds were calculated and their dependence on operating conditions (p, φ) and turbulence quantities (u′, LT) are discussed and compared to correlations from literature. No influence of pressure on the most probable flame front position or on the turbulent flame speed was observed. As expected, the equivalence ratio had a strong influence on the most probable flame front position, the spatial flame front fluctuation, and the turbulent flame speed. Decreasing the equivalence ratio results in a shift of the flame front position farther downstream due to the lower fuel concentration and the lower adiabatic flame temperature and subsequently lower turbulent flame speed. Flames operated at leaner equivalence ratios show a broader spatial fluctuation as the lean blow-out limit is approached and therefore are more susceptible to flow disturbances. In addition, because of a lower turbulent flame speed these flames stabilize farther downstream in a region with higher velocity fluctuations. This increases the fluctuation of the flame front. Flames with higher turbulence quantities (u′, LT) in the vicinity of the combustor inlet exhibited a shorter length and a higher calculated flame speed. An enhanced turbulent heat and mass transport from the recirculation zone to the flame root location due to an intensified mixing which might increase the preheating temperature or the radical concentration is believed to be the reason for that.

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An Efficient Computational Model for Premixed Turbulent Combustion at High Reynolds Numbers Based on a Turbulent Flame Speed Closure

Volume 2: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/97-gt-395 ◽

1997 ◽

Cited By ~ 8

Author(s):

Vladimir Zimont ◽

Wolfgang Polifke ◽

Marco Bettelini ◽

Wolfgang Weisenstein

Keyword(s):

Computational Model ◽

Transport Equation ◽

Turbulent Combustion ◽

Turbulent Flame ◽

Reynolds Numbers ◽

Flame Speed ◽

Closed Form Expression ◽

Turbulent Length Scale ◽

Premixed Turbulent Combustion ◽

Turbulent Flame Speed

Theoretical background, details of implementation and validation results of a computational model for turbulent premixed gaseous combustion at high turbulent Reynolds numbers are presented. The model describes the combustion process in terms of a single transport equation for a progress variable; closure of the progress variable’s source term is based on a model for the turbulent flame speed. The latter is identified as a parameter of prime significance in premixed turbulent combustion and is determined from theoretical considerations and scaling arguments, taking into account physico-chemical properties of the combustible mixture and local turbulent parameters. Specifically, phenomena like thickening, wrinkling and straining of the flame front by the turbulent velocity field are considered, yielding a closed form expression for the turbulent flame speed that involves, e.g., speed, thickness and critical gradient of a laminar flame, local turbulent length scale and fluctuation intensity. This closure approach is very efficient and elegant, as it requires only one transport equation more than the non-reacting flow case, and there is no need for costly evaluation of chemical source terms or integration over probability density functions. The model was implemented in a finite-volume based computational fluid dynamics code and validated against detailed experimental data taken from a large scale atmospheric gas turbine burner test stand. The predictions of the model compare well with the available experimental results. It has been observed that the model is significantly more robust and computationally efficient than other combustion models. This attribute makes the model particularly interesting for applications to large 3D problems in complicated geometries.

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