Flame propagation and extinction in large-scale vortical flows

2000 ◽  
Vol 120 (1-2) ◽  
pp. 222-232 ◽  
Author(s):  
L. Kagan ◽  
G. Sivashinsky
Keyword(s):  
Flame Propagation ◽  
Large Scale ◽  
Vortical Flows

Hydrogen–Air–Steam Deflagration Experiment Simulated Using Different Turbulent Flame-Speed Closure Models

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Holler Tadej ◽  
Ed M. J. Komen ◽  
Kljenak Ivo
Keyword(s):  
Flame Propagation ◽  
Nuclear Power ◽  
Large Scale ◽  
Turbulent Flame ◽  
Flame Speed ◽  
Energy Output ◽  
Combustion Model ◽  
Turbulent Flame Speed ◽  
Modeling Approach ◽  
Combustion Models

The paper presents the computational fluid dynamics (CFD) combustion modeling approach based on two combustion models. This modeling approach was applied to a hydrogen deflagration experiment conducted in a large-scale confined experimental vessel. The used combustion models were Zimont's turbulent flame-speed closure (TFC) model and Lipatnikov's flame-speed closure (FSC) model. The conducted simulations are aimed to aid identifying and evaluating the potential hydrogen risks in nuclear power plant (NPP) containment. The simulation results show good agreement with experiment for axial flame propagation using the Lipatnikov combustion model. However, substantial overprediction in radial flame propagation is observed using both combustion models, which consequently results also in overprediction of the pressure increase rate and overall combustion energy output. As assumed for a large-scale experiment without any turbulence inducing structures, the combustion took place in low-turbulence regimes, where the Lipatnikov combustion model, due to its inclusion of quasi-laminar source term, has advantage over the Zimont model.

Large-Scale Homogeneous Hydrogen-Air-Steam Deflagration Experiment Simulated Using Two Turbulent Flame Speed Closure Models

2016 ◽  
Author(s):  
Tadej Holler ◽  
Varun Jain ◽  
Ed M. J. Komen ◽  
Ivo Kljenak
Keyword(s):  
Flame Propagation ◽  
Nuclear Power ◽  
Large Scale ◽  
Turbulent Flame ◽  
Turbulent Flames ◽  
Flame Speed ◽  
Energy Output ◽  
Combustion Model ◽  
Turbulent Flame Speed ◽  
Combustion Models

The CFD combustion modeling approach based on two combustion models was applied to a hydrogen deflagration experiment conducted in a large-scale confined experimental vessel. The used combustion models were Zimont’s Turbulent Flames Speed Closure (TFC) model and Lipatnikov’s Flame Speed Closure (FSC) model. The conducted simulations are aimed to aid identifying and evaluating the potential hydrogen risks in Nuclear Power Plant (NPP) containment. The simulation results show good agreement with experiment for axial flame propagation using the Lipatnikov combustion model. However substantial overprediction in radial flame propagation is observed using both combustion models, which consequently results also in overprediction of the pressure increase rate and overall combustion energy output. As assumed for a large-scale experiment without any turbulence inducing structures, the combustion took place in low-turbulence regimes, where the Lipatnikov combustion model, due to its inclusion of quasi-laminar source term, has advantage over the Zimont model.

Experimental Investigation on Flame Propagation Speed of Rice Husk Ash in Fixed Beds

2014 ◽  
Vol 353 ◽  
pp. 96-100
Author(s):  
Chen Huang ◽  
Yi Miao Zhu ◽  
Hou Lei Zhang ◽  
Xin Zhi Liu
Keyword(s):  
Flame Propagation ◽  
Rice Husk ◽  
Large Scale ◽  
Rice Husk Ash ◽  
Fixed Bed ◽  
Propagation Speed ◽  
Low Carbon ◽  
Experimental Conditions ◽  
Long Time ◽  
Fixed Beds

Rice husk ash (RHA) is the product of rice husk pyrolysis or combustion, which contains inherent ash in original rice husk and non-converted fixed carbon. Due to large amounts of inherent silicon dioxide in rice husk, the decarbonized residue of RHA has great value as industrial materials. One basic method to remove carbon from RHA is roasting. Because of low carbon content in RHA and low roasting reaction velocity, the roasting process takes a long time. In this case, fixed-bed roasting is suitable for removing carbon from RHA. In the present work, experimental study on RHA decarbonization is conducted based on a specially-designed multi-section fixed-bed roasting. The experimental results show that under the experimental conditions, the flame propagation spread of RHA in fixed beds is in the range 0.833 to 0.121mm/s. The results documented in this paper provide the basis for further developing large-scale engineering devices.

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