Experimental and numerical study of OH* chemiluminescence in hydrogen diffusion flames

2018 ◽  
Vol 197 ◽  
pp. 369-377 ◽  
Author(s):  
Mengmeng Zhao ◽  
David Buttsworth ◽  
Rishabh Choudhury
Keyword(s):  
Hydrogen Diffusion ◽  
Diffusion Flames ◽  
Numerical Study

scholarly journals Effect of Burner Wall Material on Microjet Hydrogen Diffusion Flames near Extinction: A Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8266
Author(s):  
Aravind Muraleedharan ◽  
Jithin Edacheri Veetil ◽  
Akram Mohammad ◽  
Sudarshan Kumar ◽  
Ratna Kishore Velamati
Keyword(s):  
Thermal Radiation ◽  
Wall Thickness ◽  
Hydrogen Diffusion ◽  
Diffusion Flames ◽  
Numerical Study ◽  
Flame Temperature ◽  
Flame Height ◽  
Wall Material ◽  
Minor Effect ◽  
Near Extinction

Characteristics of microjet hydrogen diffusion flames stabilized near extinction are investigated numerically. Two-dimensional simulations are carried out using a detailed reaction mechanism. The effect of burner wall material, thickness, and thermal radiation on flame characteristics such as flame height and maximum flame temperature are studied. Results show that the flame stabilizes at lower fuel jet velocities for quartz burner than steel or aluminum. Higher flame temperatures are observed for low conductive burners, whereas the flame length increases with an increase in thermal conductivity of the burner. Even though thermal radiation has a minor effect on flame characteristics like flame temperature and flame height, it significantly influences the flame structure for low conductive burner materials. The burner tip and its vicinity are substantially heated for low conductive burners. The effect of burner wall thickness on flame height is significant, whereas it has a more negligible effect on maximum flame temperature. Variation in wall thickness also affects the distribution of H and HO2 radicals in the flame region. Although the variation in wall thickness has the least effect on the overall flame shape and temperature distribution, the structure near the burner port differs.

scholarly journals Effects of strain rate and CO2 on no formation in CH4/N2/O2 counter-flow diffusion flames

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 769-776
Author(s):  
Fei Ren ◽  
Longkai Xiang ◽  
Huaqiang Chu ◽  
Weiwei Han
Keyword(s):  
Strain Rate ◽  
Diffusion Flames ◽  
Numerical Study ◽  
Flame Temperature ◽  
Co2 Concentration ◽  
No Production ◽  
Counter Flow ◽  
Detailed Chemistry ◽  
No Formation ◽  
Key Factor

The reduction of nitrogen oxides in the high temperature flame is the key factor affecting the oxygen-enriched combustion performance. A numerical study using an OPPDIF code with detailed chemistry mechanism GRI 3.0 was carried out to focus on the effect of strain rate (25-130 s?1) and CO2 addition (0-0.59) on the oxidizer side on NO emission in CH4 / N2 / O2 counter-flow diffusion flame. The mole fraction profiles of flame structures, NO, NO2 and some selected radicals (H, O, OH) and the sensitivity of the dominant reactions contributing to NO formation in the counter-flow diffusion flames of CH4\/ N2 /O2 and CH4 / N2 / O2 / CO2 were obtained. The results indicated that the flame temperature and the amount of NO were reduced while the sensitivity of reactions to the prompt NO formation was gradually increased with the increasing strain rate. Furthermore, it is shown that with the increasing CO2 concentration in oxidizer, CO2 was directly involved in the reaction of NO consumption. The flame temperature and NO production were decreased dramatically and the mechanism of NO production was transformed from the thermal to prompt route.

Sign in / Sign up

Export Citation Format

Share Document