Laminar Burning Velocity of Methane–Air–Diluent Mixtures

2000 ◽  
Vol 123 (1) ◽  
pp. 190-196 ◽  
Author(s):  
M. Elia ◽  
M. Ulinski ◽  
M. Metghalchi
Keyword(s):  
Mass Fraction ◽  
Dynamic Pressure ◽  
Burning Velocity ◽  
Combustion Process ◽  
Numerical Differentiation ◽  
Constant Volume ◽  
Laminar Burning Velocity ◽  
Wide Range ◽  
Energy Equations ◽  
Gas Properties

An experimental facility for measuring burning velocity has been designed and built. It consists of a spherical constant volume vessel equipped with a dynamic pressure transducer, ionization probes, thermocouple, and data acquisition system. The constant volume combustion vessel allows for the determination of the burning velocity over a wide range of temperatures and pressures from a single run. A new model has been developed to calculate the laminar burning velocity using the pressure data of the combustion process. The model solves conservation of mass and energy equations to determine the mass fraction of the burned gas as the combustion process proceeds. This new method allows for temperature gradients in the burned gas and the effects of flame stretch on burning velocity. Exact calculations of the burned gas properties are determined by using a chemical equilibrium code with gas properties from the JANAF Tables. Numerical differentiation of the mass fraction burned determines the rate of the mass fraction burned, from which the laminar burning velocity is calculated. Using this method, the laminar burning velocities of methane–air–diluent mixtures have been measured. A correlation has been developed for the range of pressures from 0.75 to 70 atm, unburned gas temperatures from 298 to 550 K, fuel/air equivalence ratios from 0.8 to 1.2, and diluent addition from 0 to 15 percent by volume.

Measurement of Laminar Burning Speeds and Investigation of Flame Stability of Acetylene (C2H2)/Air Mixtures

2014 ◽  
Author(s):  
Emad Rokni ◽  
Ali Moghaddas ◽  
Omid Askari ◽  
Hameed Metghalchi
Keyword(s):  
Flame Propagation ◽  
High Speed ◽  
Dynamic Pressure ◽  
Combustion Process ◽  
Pressure Rise ◽  
Laminar Flames ◽  
Cmos Camera ◽  
Wide Range ◽  
Cellular Flames ◽  
Flame Structures

Laminar burning speeds and flame structures of spherically expanding flames of mixtures of acetylene (C2H2) with air have been investigated over a wide range of equivalence ratios, temperatures, and pressures. Experiments have been conducted in a constant volume cylindrical vessel with two large end windows. The vessel was installed in a shadowgraph system equipped with a high speed CMOS camera, capable of taking pictures up to 40,000 frames per second. Shadowgraphy was used to study flame structures and transition from smooth to cellular flames during flame propagation. Pressure measurements have been done using a pressure transducer during the combustion process. Laminar burning speeds were measured using a thermodynamic model employing the dynamic pressure rise during the flame propagation. Burning speeds were measured for temperature range of 300 to 590 K and pressure range of 0.5 to 3.3 atmospheres, and the range of equivalence ratios covered from 0.6 to 2. The measured values of burning speeds compared well with existing data and extended for a wider range of temperatures. Burning speed measurements have only been reported for smooth and laminar flames.

Experimental and Computational Determination of LBV of Hydrogen Enriched Methane Mixtures

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Vinod Kumar Yadav ◽  
Ranjeet Singha ◽  
Abhishek Kumar Pandey ◽  
Saumya   ◽  
Ashish Kumar Singh ◽  
...  
Keyword(s):  
Coming Out ◽  
Burning Velocity ◽  
Laminar Burning Velocity ◽  
Flammability Limits ◽  
Ambient Temperatures ◽  
Gaseous Fuels ◽  
Wide Range ◽  
Hydrogen Enrichment ◽  
Institute Of Technology ◽  
Set Up

One of the major causes of environmental pollution and ozone layer depletion is the emissions coming out of the combustion devices including industrial burners, automobile vehicles and household appliances. Most of the conventional fuels used now days have high GWP and ODP. So the greatest challenges among the combustion researchers and scientists are to develop some sustainable and non conventional sources of energy that possesses capability to replace the conventional ones. One of the important gaseous fuels in non conventional category is hydrogen, which is a cleaner fuel and reduces pollution enormously. In the present work, experimental & computational analysis of laminar burning velocity (LBV) of premixed gaseous fuels (primary focus on Hydrogen enrichment) was carried out. For experimental investigation the experimental set up available in Fuel and pollution lab of Indian Institute of Technology Delhi is used. Experiments were carried out on mixtures of methane- Air and Methane-Hydrogen-Air for wide range of equivalence ratios and compared with the computational results of PREMIX with full GRI-Mech 3.0 mechanism. Most of the experiments available in literature were carried out at 298 K. In the present work it has been tried to relate the effect of low temperatures on laminar burning velocity of mixtures. The experiments have been conducted at 1 bar pressure and around 292 Kelvin with equivalence ratio ranging from 0.8 to 1.2. Methane gas is enriched with hydrogen in varying proportions and the effect of hydrogen enrichment on its laminar burning velocity studied. The objective of the addition of hydrogen to methane was to increase its laminar burning velocity as well as to extend its lean flammability limits at lower ambient temperatures.

Measurement of Laminar Burning Speeds and Determination of Onset of Auto-Ignition of Jet-A/Air and Jet Propellant-8/Air Mixtures in a Constant Volume Spherical Chamber

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Ali Moghaddas ◽  
Casey Bennett ◽  
Kian Eisazadeh-Far ◽  
Hameed Metghalchi
Keyword(s):  
High Pressures ◽  
Dynamic Pressure ◽  
Combustion Process ◽  
Pressure Rise ◽  
Constant Volume ◽  
Pressure Data ◽  
Spherical Vessel ◽  
Auto Ignition ◽  
Made In

The laminar burning speeds of Jet-A/air and three different samples of jet propellant (JP-8)/air mixtures have been measured and the onset of auto-ignition in JP-8/air premixed mixtures has been determined. The experiments were made in a constant volume spherical vessel, which can withstand high pressures up to 400 atm. Burning speed was calculated from dynamic pressure rise due to the combustion process in the vessel. A thermodynamic model based on the pressure rise was used to determine the burning speed. The burning speeds were measured in lean mixtures for pressures of 1–4.5 atm and temperatures of 493–700 K. The onset of auto-ignition of JP-8 fuels was evaluated by observing intense fluctuations of pressure data during the explosion of the unburned gas. It was revealed that Jet-A and JP-8 have very similar burning speeds; however, auto-ignition temperatures of various samples of JP-8 were slightly different from each other. Auto-ignition of these fuels was much more sensitive to temperature rather than pressure.

scholarly journals Aqueous ethanol laminar burning velocity measurements using constant volume bomb methods

Fuel ◽  
2018 ◽  
Vol 214 ◽  
pp. 127-134 ◽  
Author(s):  
N. Hinton ◽  
R. Stone ◽  
Roger Cracknell ◽  
Carsten Olm
Keyword(s):  
Aqueous Ethanol ◽  
Burning Velocity ◽  
Constant Volume ◽  
Laminar Burning Velocity ◽  
Velocity Measurements

scholarly journals Effect of Hydrogen Content and Dilution on Laminar Burning Velocity and Stability Characteristics of Producer Gas-Air Mixtures

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
V. Ratna Kishore ◽  
M. R. Ravi ◽  
Anjan Ray
Keyword(s):  
Hydrogen Content ◽  
Alternative Fuels ◽  
Burning Velocity ◽  
Operating Conditions ◽  
Producer Gas ◽  
Laminar Burning Velocity ◽  
High Hydrogen ◽  
Promising Alternative ◽  
Preferential Diffusion ◽  
Wide Range

Producer gas is one of the promising alternative fuels with typical constituents of H2, CO, CH4, N2, and CO2. The laminar burning velocity of producer gas was computed for a wide range of operating conditions. Flame stability due to preferential diffusional effects was also investigated. Computations were carried out for spherical outwardly propagating flames and planar flames. Different reaction mechanisms were assessed for the prediction of laminar burning velocities of CH4, H2, H2-CO, and CO-CH4and results showed that the Warnatz reaction mechanism with C1 chemistry was the smallest among the tested mechanisms with reasonably accurate predictions for all fuels at 1 bar, 300 K. To study the effect of variation in the producer gas composition, each of the fuel constituents in ternary CH4-H2-CO mixtures was varied between 0 to 48%, while keeping diluents fixed at 10% CO2and 42% N2by volume. Peak burning velocity shifted fromϕ=1.6to 1.1 as the combined volumetric percentage of hydrogen and CO varied from 48% to 0%. Unstable flames due to preferential diffusion effects were observed for lean mixtures of fuel with high hydrogen content. The present results indicate that H2has a strong influence on the combustion of producer gas.

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