scholarly journals EXPERIMENTAL DETERMINATION OF LAMINAR BURNING VELOCITY OF BIOGAS AT PRESSURES UP TO 5 BAR

2018 ◽  
Vol 17 (2) ◽  
pp. 03
Author(s):  
L. Pizzuti ◽  
C. A. Martins ◽  
L. R. Santos
Keyword(s):  
Equivalence Ratio ◽  
Burning Velocity ◽  
Initial Pressure ◽  
Experimental Setup ◽  
Laminar Burning Velocity ◽  
Gaseous Mixtures ◽  
Experimental Procedure ◽  
Constant Volume Combustion Chamber ◽  
Percentage Standard Deviation

This paper presents a very detailed description of a new cylindrical constant volume combustion chamber designed for laminar burning velocity determination of gaseous mixtures at ambient temperature and initial pressure up to 6 bar. The experimental setup, the experimental procedure and the determination of the range of flame radius for laminar burning determination are all described in details. The laminar burning velocity of twelve synthetic biogas mixtures has been studied. Initial pressure varying between 1 and 5 bar, equivalence ratios, f, between 0.7 and 1.1 and percentage dilution, with a mixture of CO2 and N2, between 35 and 55% have been considered. Five experiments were run for each mixture providing a maximum percentage standard deviation of 8.11%. However, for two third of the mixtures this value is lower than 3.55%. A comparison with simulation using PREMIX for both GRI-Mech 3.0 and San Diego mechanisms has provided closer agreement for mixtures with equivalence ratio closer to stoichiometry whereas for f = 0.7 the deviation is larger than 15% for all pressures. Mixtures with lower equivalence ratio, higher dilution percentage and higher initial pressure presents the lower values of laminar burning velocity.

FLAME PROPAGATION AND BURNING RATES OF METHANE-AIR MIXTURES USING SCHLIEREN PHOTOGRAPHY

2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Mohd Suardi Suhaimi ◽  
Aminuddin Saat ◽  
Mazlan A. Wahid ◽  
Mohsin Mohd Sies
Keyword(s):  
Combustion Chamber ◽  
Burning Rate ◽  
Equivalence Ratio ◽  
Burning Velocity ◽  
Initial Pressure ◽  
Markstein Length ◽  
Constant Volume Combustion Chamber ◽  
Burning Rates ◽  
Schlieren Photography

Different methodology have been shown to produce different results for Markstein length and laminar burning velocity of methane-air mixture.This study attempts to determine the aforesaid parameters using the newly developed closed vessel combustion chamber with Schlieren photography. Markstein length and burning rate of methane-air mixture was determined under the initial pressure of 1 atm, temperature range of 298-302K and equivalence ratio range of 0.7-1.3. Experiments were performed in a centrally ignited 29.16L cylindrical constant volume combustion chamber. Ignition energy was set at 25mJ for each experiment. The images of spherically expanding flame were recorded using Schlieren photography technique at a speed of 2000 frame per second. Analysis of the flame area yield flame radii from which the flame speed and stretch rate could be obtained. These parameters would allow the determination of Markstein length and burning rate of the flame. Results show that Markstein length magnitude increases proportionally with equivalence ratio with a magnitude ranging from 0.125cm to 0.245cm. Maximum burning rate occurs at equivalence ratio of 1.1 with a magnitude of 0.366 m/s. Flame of each equivalence ratio also exhibits fluctuation arising from acoustic disturbance. This disturbance becomes more apparent at higher equivalence ratio.

Characteristics of Ammonia-Nitric Oxide Combustion

2003 ◽  
Author(s):  
Rui Liu ◽  
David S.-K. Ting ◽  
M. David Checkel
Keyword(s):  
Nitric Oxide ◽  
Reaction Mechanisms ◽  
Equivalence Ratio ◽  
Burning Velocity ◽  
Flame Temperature ◽  
Laminar Burning Velocity ◽  
Flammability Limits ◽  
Constant Volume Combustion Chamber ◽  
Experimental Values ◽  
Peak Value

The combustion characteristics of premixed ammonia-nitric oxide mixtures at atmospheric and elevated conditions were numerically examined. The laminar burning velocity, flame temperature and flammability limits were determined using the GRI 3.0 and the Miller-Bowman 1989 reaction mechanisms in CHEMKIN. A freely propagating adiabatic flame was assumed to facilitate the investigation. The laminar burning velocities and the flammability limits predicted with the two mechanisms were compared with experimental values measured in a constant volume combustion chamber. The predicted flammability limits are at ammonia-nitric oxide equivalence ratios of 0.2 and 3.5. The predicted laminar burning velocity increases with the unburnt mixture temperature and decreases with the pressure with a peak value at ammonia-nitric oxide equivalence ratio of 0.9. The Miller-Bowman 1989 mechanism predicts results closer to the measured values than the GRI 3.0 mechanism when the laminar burning velocity is concerned. For the adiabatic flame temperature, the predictions from both mechanisms agree well with each other.

Determination of global kinetic parameters by optimization procedure using burning velocity measurements

2018 ◽  
Vol 13 (6) ◽  
pp. 50
Author(s):  
Gleb V. Grenkin ◽  
Alexander Yu. Chebotarev ◽  
Valeri I. Babushok ◽  
Sergey S. Minaev
Keyword(s):  
Kinetic Parameters ◽  
Equivalence Ratio ◽  
Reaction Rate ◽  
Functional Dependence ◽  
Burning Velocity ◽  
Optimization Procedure ◽  
Optimal Parameters ◽  
Velocity Measurements ◽  
Equilibrium Calculations

The optimization procedure was developed to derive the global kinetic parameters using experimental dependence of burning velocity on the equivalence ratio. The simple model of laminar premixed flame propagation with assumed constant parameters was used to demonstrate the features of the suggested procedure. The suggested method allows finding optimal parameters for the defined functional dependence of the reaction rate on the temperature and reactant concentrations. The dependence of combustion adiabatic temperature on equivalence ratio is assumed to be known from the flame equilibrium calculations. The global kinetic parameters of combustion reaction were determined for methane, ethylene and propane mixtures with air on the basis of experimental data on burning velocity as function of the equivalence ratio. The calculated overall kinetic parameters are compared with parameters obtained by other methods within similar global model.

scholarly journals PENENTUAN ANGKA OKTANA BAHAN BAKAR KOMERSIAL DENGAN MENGGUNAKAN MODEL KINETIKA OKSIDASI DAN PEMBAKARAN HIDROKARBON MULTIKOMPONEN

REAKTOR ◽  
2012 ◽  
Vol 14 (2) ◽  
pp. 109 ◽  
Author(s):  
Yuswan Muharam ◽  
Chandra Hadiwijaya ◽  
Jacquin Suryadi
Keyword(s):  
Old Age ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Initial Pressure ◽  
Volume Percentage ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Commercial Fuel ◽  
Good Agreement

One of the characteristics of gasoline fuel is anti-knock property represented by its octanenumber. The determination of octane numbers in Indonesia is by using cooperative fuel researchengines. The usage of cooperative fuel research engines in Indonesia has constraints, i.e. the limitednumber of the units and the old age. This study aims to obtain the octane numbers of commercialfuels by using kinetic models. The kinetics models of the oxidation and combustion of primaryreference fuel and multi component hydrocarbons are used to calculate the ignition delay times ofprimary reference fuel and commercial fuels, respectively. The ignition delay times of primaryreference fuel and commercial fuels are calculated at the same initial pressure and temperature, aswell as the same equivalence ratio. The octane number of a commercial fuel is known if its ignitiondelay time agrees with that of PFR possessing a certain volume percentage of isooctane. The modelgenerates the octane numbers of commercial fuels BB-A being 92.5, BB-B being 94.5, BB-C being89, BB-D being 90.5 and BB-E being 91.5 with the good agreement with those claimed by the fuelproducers. Salah satu karakteristik bahan bakar bensin adalah sifat anti ketukan yang dinyatakan dengan angkaoktana. Penentuan angka oktana di Indonesia menggunakan mesin CFR (cooperative fuel research).Pemakaian mesin CFR di Indonesia memiliki kendala, yaitu jumlah unit terbatas dan usia tua.Penelitian ini bertujuan mendapatkan angka oktana bahan bakar komersial dengan menggunakanmodel kinetika. Model kinetika oksidasi dan pembakaran bahan bakar rujukan utama dan modelhidrokarbon multikomponen yang telah divalidasi masing-masing digunakan untuk menghitungwaktu tunda ignisi bahan bakar rujukan utama dan bahan bakar komersial. Waktu tunda ignisibahan bakar rujukan utama dan bahan bakar komersial dihitung pada tekanan dan temperatur awal,serta rasio ekuivalensi yang sama. Angka oktana suatu bahan bakar komersial diketahui apabilawaktu tunda ignisinya cocok dengan waktu tunda ignisi bahan bakar rujukan utama yang memilikipersen volume isooktana tertentu. Model menghasilkan angka oktana bahan bakar komersial BB-Asebesar 92,5, BB-B 94,5, BB-C 89, BB-D 90,5 dan BB-E 91,5 yang memiliki ketepatan yang tinggiterhadap klaim produser bahan bakar komersial.

Determination of the laminar burning velocity and the Markstein length of powder–air flames

2002 ◽  
Vol 122 (2-3) ◽  
pp. 222-238 ◽  
Author(s):  
A.E. Dahoe ◽  
K. Hanjalic ◽  
B. Scarlett
Keyword(s):  
Burning Velocity ◽  
Laminar Burning Velocity ◽  
Markstein Length

Development of a Simulation Code for Hydrogen Fuelled SI Engines

2006 ◽  
Author(s):  
Sebastian Verhelst ◽  
Roger Sierens ◽  
Stefaan Verstraeten
Keyword(s):  
Alternative Energy ◽  
Equivalence Ratio ◽  
Internal Combustion Engines ◽  
Burning Velocity ◽  
Combustion Model ◽  
Laminar Burning Velocity ◽  
Velocity Correlation ◽  
Model Framework ◽  
Economic Point ◽  
Velocity Models

Hydrogen is an attractive alternative energy carrier, which could make harmful emissions, global warming and the insecurity concerning oil supply a thing of the past. Hydrogen internal combustion engines can be introduced relatively easily, from a technological as well as from an economic point of view. This paper discusses the development of a model for the combustion of hydrogen in spark ignition engines, which has lead to a simulation program that can assist the optimization of these engines. The importance of a laminar burning velocity correlation taking stretch and instability effects into account is shown. The effects are particularly strong for the highly diffusive hydrogen molecule. In this paper, a laminar burning velocity correlation published previously by two of the authors is combined with a number of turbulent burning velocity models in a quasi-dimensional two-zone combustion model framework. After calibration of the combustion model for a reference condition, simulation results are compared with experimental cylinder pressure data recorded on a single cylinder hydrogen engine. Correspondence between simulation and measurement is shown for varying equivalence ratio, ignition timing and compression ratio. All models performed well for varying ignition timings and compression ratios; the real test proved to be the ability of the models to predict the effects of a varying equivalence ratio, this lead to a clear distinction in the models.

Experimental Study on Laminar Flame Speeds and Markstein Length of Methane-Air Mixtures at Atmospheric Conditions

2014 ◽  
Vol 699 ◽  
pp. 714-719
Author(s):  
Alaeldeen Altag Yousif ◽  
Shaharin Anwar Sulaiman
Keyword(s):  
High Speed ◽  
Equivalence Ratio ◽  
Laminar Flame ◽  
Burning Velocity ◽  
Ambient Pressure ◽  
Flame Speed ◽  
Laminar Flame Speed ◽  
Atmospheric Conditions ◽  
Laminar Burning Velocity ◽  
Markstein Length

Accurate value of laminar flame speed is an important parameter of combustible mixtures. In this respect, experimental data are very useful for modeling improvement and validating chemical kinetic mechanisms. To achieve this, an experimental characterization on spherically expanding flames propagation of methane-air mixtures were carried out. Tests were conducted in constant volume cylindrical combustion chamber to measure stretched, unstretched laminar flame speed, laminar burning velocity, and flame stretch effect as quantified by the associated Markstein lengths. The mixtures of methane-air were ignited at extensive ranges of lean-to-rich equivalence ratios, under ambient pressure and temperature. This is achieved by high speed schlieren cine-photography for flames observation in the vessel. The results showed that the unstretched laminar burning velocity increased and the peak value of the unstretched laminar burning velocity shifted to the richer mixture side with the increase of equivalence ratio. The flame propagation speed showed different trends at different equivalence ratio for tested mixtures. It was found that the Markstein length was increased with the increase of equivalence ratio.

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