scholarly journals A Numerical Study on Effect of Vortex Core Radius on Premixed Flame Propagation in Rankin Vortex Flow

2008 ◽  
Vol 74 (747) ◽  
pp. 2387-2392
Author(s):  
Shuuji KONDOU ◽  
Hiroshi YAMASHITA ◽  
Masahisa SHINODA ◽  
Kazuhiro YAMAMOTO
Keyword(s):  
Flame Propagation ◽  
Vortex Core ◽  
Vortex Flow ◽  
Numerical Study ◽  
Premixed Flame ◽  
Core Radius

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.

On the effects of microbubbles on Taylor–Green vortex flow

2007 ◽  
Vol 572 ◽  
pp. 145-177 ◽  
Author(s):  
ANTONINO FERRANTE ◽  
SAID E. ELGHOBASHI
Keyword(s):  
Decay Rate ◽  
Vortex Core ◽  
Vortex Flow ◽  
Volume Fraction ◽  
Numerical Study ◽  
Fluid Velocity ◽  
The Core ◽  
Vorticity Dynamics ◽  
The Mean ◽  
Two Fluid

The paper describes a numerical study of the effects of microbubbles on the vorticity dynamics in a Taylor–Green vortex flow (TGV) using the two-fluid approach. The results show that bubbles with a volume fraction ∼10−2 enhance the decay rate of the vorticity at the centre of the vortex. Analysis of the vorticity equation of the bubble-laden flow shows that the local positive velocity divergence of the fluid velocity, ∇·U, created in the vortex core by bubble clustering, is responsible for the vorticity decay. At the centre of the vortex, the vorticity ωc(t) decreases nearly linearly with the bubble concentration Cm(t). Similarly, the enstrophy in the core of the vortex, ω2(t), decays nearly linearly with C2(t). The approximate mean-enstrophy equation shows that bubble accumulation in the high-enstrophy core regions produces a positive correlation between ω2 and ∇·U, which enhances the decay rate of the mean enstrophy.

Numerical study of pressure and composition influence on laminar flame propagation in nitrogen-diluted H2-O2 mixtures

2020 ◽  
Vol 65 (6) ◽  
pp. 529-537
Author(s):  
Domnina RAZUS ◽  
◽  
Maria MITU ◽  
Venera GIURCAN ◽  
Codina MOVILEANU ◽  
...  
Keyword(s):  
Flame Propagation ◽  
Laminar Flame ◽  
Numerical Study
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