Numerical Simulation of Premixed Propane/Air Flame Propagation Using a Dynamically Thickened Flame Approach

2013 ◽  
Vol 444-445 ◽  
pp. 1574-1578 ◽  
Author(s):  
Hua Hua Xiao ◽  
Zhan Li Mao ◽  
Wei Guang An ◽  
Qing Song Wang ◽  
Jin Hua Sun
Keyword(s):  
Numerical Simulation ◽  
Flame Propagation ◽  
Numerical Study ◽  
Vortex Motion ◽  
Combustion Process ◽  
Single Step ◽  
Premixed Combustion ◽  
Premixed Flame ◽  
Flame Surface ◽  
Arrhenius Kinetics

A numerical study of premixed propane/air flame propagation in a closed duct is presented. A dynamically thickened flame (TF) method is applied to model the premixed combustion. The reaction of propane in air is taken into account using a single-step global Arrhenius kinetics. It is shown that the premixed flame undergoes four stages of dynamics in the propagation. The formation of tulip flame phenomenon is observed. The pressure during the combustion process grows exponentially at the finger-shape flame stage and then slows down until the formation of tulip shape. After tulip formation the pressure increases quickly again with the increase of the flame surface area. The vortex motion behind the flame front advects the flame into tulip shape. The study indicates that the TF model is quite reliable for the investigation of premixed propane/air flame propagation.

scholarly journals The evolution equation for the flame surface density in turbulent premixed combustion

1994 ◽  
Vol 278 ◽  
pp. 1-31 ◽  
Author(s):  
Arnaud Trouvé ◽  
Thierry Poinsot
Keyword(s):  
Evolution Equation ◽  
Flame Propagation ◽  
Surface Density ◽  
Turbulent Flame ◽  
Premixed Combustion ◽  
Flame Surface ◽  
Turbulent Premixed Combustion ◽  
Flame Surface Density ◽  
Propagation Effects ◽  
Turbulent Premixed

One basic effect of turbulence in turbulent premixed combustion is for the fluctuating velocity field to wrinkle the flame and greatly increase its surface area. In the flamelet theory, this effect is described by the flame surface density. An exact evolution equation for the flame surface density, called the Σ-equation, may be written, where basic physical mechanisms like production by hydrodynamic straining and destruction by propagation effects are described explicitly. Direct numerical simulation (DNS) is used in this paper to estimate the different terms appearing in the Σ-equation. The numerical configuration corresponds to three-dimensional premixed flames in isotropic turbulent flow. The simulations are performed for various mixture Lewis numbers in order to modify the strength and nature of the flame-flow coupling. The DNS-based analysis provides much information relevant to flamelet models. In particular, the flame surface density, and the source and sink terms for the flame surface density, are resolved spatially across the turbulent flame brush. The geometry as well as the dynamics of the flame differ quite significantly from one end of the reaction zone to the other. For instance, contrary to the intuitive idea that flame propagation effects merely counteract the wrinkling due to the turbulence, the role of flame propagation is not constant across the turbulent brush and switches from flame surface production at the front to flame surface dissipation at the back. Direct comparisons with flamelet models are also performed. The Bray-Moss-Libby assumption that the flame surface density is proportional to the flamelet crossing frequency, a quantity that can be measured in experiments, is found to be valid. Major uncertainties remain, however, over an appropriate description of the flamelet crossing frequency. In comparison, the coherent flame model of Marble & Broadwell achieves closure at the level of the Σ-equation and provides a more promising physically based description of the flame surface dynamics. Some areas where the model needs improvement are identified.

Analysis of Flame Propagation in Stratified Mixture by Numerical Simulation of Counter flow Premixed flame

2002 ◽  
Vol 2002.55 (0) ◽  
pp. 195-196
Author(s):  
Toshiaki KITAGAWA ◽  
Hiroyuki KIDO ◽  
KyuSung KIM ◽  
Hirotaka KOGA ◽  
Kazutaka FUJIOKA ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flame Propagation ◽  
Premixed Flame ◽  
Counter Flow

scholarly journals Numerical Implementation and validation of turbulent premixed combustion model for lean mixtures

2018 ◽  
Vol 209 ◽  
pp. 00004 ◽  
Author(s):  
Siva Muppala ◽  
Vendra C. Madhav Rao
Keyword(s):  
Equivalence Ratio ◽  
Numerical Study ◽  
Premixed Combustion ◽  
Reacting Flow ◽  
Flame Surface ◽  
Parametric Variation ◽  
Turbulent Flame Speed ◽  
Preferential Diffusion ◽  
Good Agreement ◽  
Turbulent Premixed

The present paper discusses the numerical investigation of turbulent premixed flames under lean conditions. Lean premixed combustion, a low NOx emission technique but are prone to instabilities, extinction and blow out. Such flames are influenced by preferential diffusion due to different mass diffusivities of reactants and difference between heat and mass diffusivities in the reaction zone. In this numerical study, we estimate non-reacting flow characteristics with implementation of an Algebraic Flame Surface Wrinkling Model (AFSW) in the open source CFD code OpenFOAM. In these flows, the mean velocity fields and recirculation zones were captured reasonably well by the RANS standard k-epsilon turbulence model. The simulated turbulent velocity is in good agreement with experiments in the shear-generated turbulence layer. The reacting flow study was done at three equivalence ratios of 0.43, 0.5 and 0.56 to gauge the ability of numerical model to predict combustion quantities. At equivalence ratios 0.5 and 0.56 the simulations showed numerical oscillations and non-convergence of the turbulent quantities. This leads to a detailed parametric variation study where, the pre-constant of AFSW model is varied with values 0.3, 0.35 and 0.4. However the study revealed the weak dependence of pre-constant value on the equivalence ratio. Hence the pre-constant value is fit for specific equivalence ratio based on the parametric variation study. The tuned AFSW model with fitted pre-constant specific to given equivalence ratio predicted are compared with experiments and discussed. The tuned AFSW model produced turbulent flame speed values which are good agreement with experiments.

Numerical simulation of premixed flame propagation in a closed tube

1996 ◽  
Vol 18 (3) ◽  
pp. 165-182 ◽  
Author(s):  
Kazuto Kuzuu ◽  
Katsuya Ishii ◽  
Kunio Kuwahara
Keyword(s):  
Numerical Simulation ◽  
Flame Propagation ◽  
Premixed Flame ◽  
Closed Tube

Optimized single-step (OSS) chemistry models for the simulation of turbulent premixed flame propagation

2018 ◽  
Vol 192 ◽  
pp. 130-148 ◽  
Author(s):  
Aimad Er-raiy ◽  
Zakaria Bouali ◽  
Julien Réveillon ◽  
Arnaud Mura
Keyword(s):  
Flame Propagation ◽  
Single Step ◽  
Premixed Flame ◽  
Turbulent Premixed Flame ◽  
Turbulent Premixed

Simulation Study about Dual Spark Plug Position for the CNG Engine Combustion Process

2013 ◽  
Vol 712-715 ◽  
pp. 1197-1200 ◽  
Author(s):  
Chang Qing Song ◽  
Jun Li ◽  
Da Wei Qu ◽  
Kai Yu
Keyword(s):  
Flame Propagation ◽  
Combustion Process ◽  
Three Dimensional ◽  
Propagation Distance ◽  
Simulation Software ◽  
Flame Surface ◽  
Flame Kernel ◽  
Spark Plug ◽  
Cng Engine ◽  
Combustion Speed

The paper has modeled and simulated the combustion process of big bore CNG engine by three-dimensional simulation software AVL FRIE. Based on test validation in the model, the effect on position of the dual spark plug for cylinder initial flame kernel development and flame propagation process was researched. The results showed that: When A=0.5, the flame propagation distance shortened by half, a certain intensity of turbulence formed when the compression stroke ended, the combustion speed was the fastest, the combustion duration was the shortest. If dual spark plug spacing is too small, the two flames meet prematurely will cause interfere with each other, and reduce the combustion speed of the overlapping region of the flame surface, increase the heat losses. Otherwise,if the distance is too large , close to the combustion chamber wall, the combustion space is narrow, the flame propagation space is restricted, then flame development is slow.

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