npsAE78

7/28/2019 npsAE78

1/9

International Journal of Hydrogen Energy 26 (2001) 265273

www.elsevier.com/locate/ijhydene

Eects of addition of electrolysis products on methane=airpremixed laminar combustion

C. Uykura, P.F. Henshawb; , D.S.-K. Tinga, R.M. Barrona

aMechanical Engineering, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, Canada N9B 3P4bCivil and Environmental Engineering, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, Canada N9B 3P4

Abstract

In this study, eects of the addition of small amounts of water electrolysis products on laminar premixed methane =air

ames have been investigated using chemical kinetic simulation methods. The CHEMKIN kinetic simulation package was

used with the GRI kinetic mechanism. Pollutant concentrations, ame speeds, temperature proles and lean ammability

limits of methane=air, methane=hydrogen=air and methane=hydrogen=oxygen=air systems were compared at dierent addition

percentages and equivalence ratios from 1.4 to the lean ammability limit. The addition of 10 20% hydrogen in the fuel

was found to have a small eect in improving ame speed and lean ammability limit properties. However, the addition of

oxygen and hydrogen in the same ratio as is found in water was shown to be benecial. Improvements in the ame speeds

of methane=air mixtures by the addition of 10% hydrogen and its associated oxygen were equivalent to the improvements

obtained by the addition of 20% hydrogen only. In near stoichiometric mixtures, the addition of oxygen substantially increased

the NOx concentrations, but for lean mixtures no increase in NOx was predicted. CO emissions were reduced when hydrogen

displaced carbon-containing fuels. ? 2001 International Association for Hydrogen Energy. Published by Elsevier Science

Ltd. All rights reserved.

Keywords: Water electrolysis products; Kinetic simulation; Hydrogen; Methane; Oxygen; CHEMKIN; GRI

1. Introduction

Natural gas, which is mainly composed of methane, oers

signicant economic [1] and environmental [2,3] advantages

over other fuels. Methane has lower emission levels com-

pared with other fuels because of its chemical formula (lower

carbon to hydrogen ratio) and utilizing it in leaner combus-tion can further reduce these levels. Leaner combustion of

methane may result in higher thermal eciency and reduced

emissions, especially of NOx . However, the low ignitibility

and lower ame speed of methane, which cause combustion

instabilities, excessive emissions and lower power output,

are the major impediments to achieving satisfactory results

with methane.

Corresponding author. Tel.: +01-519-253-4232 ext 2588; fax:

+01-519-971-3686.

E-mail address: [email protected] (P.F. Henshaw).

A practical solution to overcome the diculties with

methane is addition of more reactive fuels such as hydrogen.

There have been several investigations on the eects of the

addition of hydrogen into methane. It has been shown both

theoretically and experimentally that hydrogen addition

results in substantial enhancement in the ignitibility and

lean ammability limits of methane=air mixtures [417].Production of hydrogen by electrolysis of water may be

preferred because of the safety and cost considerations of

handling and storing hydrogen as a fuel additive [18,19].

The oxygen by-product of electrolysis can also be added

into the fuel=oxidizer mixture in order to improve combus-

tion properties. Practical applications of the addition of elec-

trolysis products into other fuels are already available in

the market. Although investigations concerning the utiliza-

tion of electrolysis products in practical devices such as IC

engines were performed in several studies [20,21], some

fundamental research is still needed to better understand

combustion kinetics of these mixtures without the compli-cations of operating a practical combustion device.

0360-3199/01/$ 20.00 ? 2001 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.

PII: S 0 3 6 0 - 3 1 9 9 ( 0 0 ) 0 0 0 6 8 - 9

7/28/2019 npsAE78

2/9

266 C. Uykur et al. / International Journal of Hydrogen Energy 26 (2001) 265273

In this study, the eects of the addition of small amounts

of hydrogen on methane=air combustion of premixed, lami-

nar, freely propagating, planar ames has been theoretically

investigated. In addition, since electrolysis of water may be

the source of hydrogen, the addition of hydrogen and oxy-

gen in the molar ratio H2 : O2 = 2 : 1 into a methane=airburner has been simulated.

2. The model

The numerical simulation was performed in order to pre-

dict adiabatic ame temperatures, pollutant concentrations

and ame speeds of laminar, premixed, freely propagating,

one-dimensional ames. The computational model used in

this study consists of the following components: PREMIX

[22], Sandias steady state, laminar, one-dimensional ame

code; TWOPNT [22], a boundary value problem solver;

a transport property preprocessor [22]; CHEMKIN-III [23],

a gas-phase interpreter which processes the chemical re-

action mechanism; and GRI 3.0 [24], a chemical reaction

mechanism for methane combustion.

PREMIX code which uses a hybrid time-integration=

Newton iteration technique to solve the steady-state com-

prehensive mass, species, and energy conservation equa-

tions was set up to simulate a freely propagating ame

with mixture-averaged formulas. An additional boundary

condition for mass ow rate, which is necessary for this

type of formulation, was obtained by xing the location of

the ame by specifying the temperature at one point. The

CHEMKIN package was modied to implement the GRImechanism by replacing its original reaction and transport

library with the GRI les. In this study, the GRI mechanism

version 3.0, which has 325 reactions and 53 species, was

used without any modication. The mechanism is described

extensively elsewhere [24].

The problem environment was dened by setting the ini-

tial and boundary conditions. The initial ow rate estimation

of the fuel=oxidizer mixture was set equal to 0:04 (g=cm2 s)

according to the published measurements of stoichiometric

methane=air ame speeds [25]. The pressure and tempera-

ture of the mixture were set at 1.0 atm and 298 K, respec-

tively. The additional boundary condition required for theow solution was supplied by xing the temperature point

for 400 K whose distance is calculated from the initial tem-

perature prole estimation by the software. Since it was

known from the previous studies [26] that the total reaction

zone of the premixed, laminar, freely propagating, stoichio-

metric methane=air ame is about 0.4 cm, the calculation

domain was started 2 cm before the ame region and the

total length of the calculation domain was chosen as 12 cm.

The initial temperature prole estimation, which is required

to start the iteration, was made according to the recent study

of VanMaaren et al. [26]. Results of the rst simulation step

were used as the temperature prole estimation for the next

step.

Table 1

Unreacted fueloxidizer composition of methane=air mixtures at

dierent equivalence ratios

O2 N2 CH4

1.5 0.1811 0.6831 0.13581.4 0.1827 0.6894 0.1279

1.3 0.1844 0.6957 0.1199

1.2 0.1861 0.7022 0.1117

1.1 0.1879 0.7088 0.1033

1 0.1896 0.7155 0.0948

0.9 0.1915 0.7224 0.0862

0.8 0.1933 0.7294 0.0773

0.7 0.1952 0.7365 0.0683

0.6 0.1971 0.7437 0.0591

0.5 0.1991 0.7511 0.0498

Table 2

Unreacted fueloxidizer composition of methane=air mixture with

the addition of 10% hydrogen by volume at dierent equivalence

ratios

O2 N2 CH4 H2

1.5 0.1791 0.6757 0.1307 0.0145

1.4 0.1808 0.6823 0.1232 0.0137

1.3 0.1826 0.6890 0.1155 0.0128

1.2 0.1844 0.6959 0.1077 0.0120

1.1 0.1863 0.7029 0.0997 0.0111

1 0.1882 0.7101 0.0916 0.0102

0.9 0.1901 0.7174 0.0832 0.0092

0.8 0.1921 0.7248 0.0748 0.0083

0.7 0.1941 0.7324 0.0661 0.00730.6 0.1962 0.7402 0.0573 0.0064

0.5 0.1983 0.7481 0.0482 0.0054

Numerical solutions were obtained for the following

mixtures: (1) pure methane=air, (2) 10% hydrogen + 90%

methane+air, (3) 20% hydrogen + 80% methane + air, (4)

10% hydrogen + oxygen (half as much as the hydrogen) +

90% methane + air (the initial concentrations of these mix-

tures can be found in Tables 14). Lean ammability

limits, nal temperature proles, ame speeds and species

concentration of these mixtures have been predicted fordierent equivalence ratios ().

3. Results and discussion

The solution algorithm was rst tested for accuracy by

comparing the ame speed at dierent equivalence ratios of

pure methane=air mixtures to published values. The ame

speed is dened as the speed, relative to and normal to the

ame front, with which unburned gas moves into the front

and is transformed to products under laminar ow condi-

tions [29]. In our study it was simply the velocity of gas

ow at the adiabatic boundary of the ame (ow velocity

7/28/2019 npsAE78

3/9

C. Uykur et al. / International Journal of Hydrogen Energy 26 (2001) 265273 267

Table 3

Unreacted fueloxidizer composition of methane=air mixture with

the addition of 20% hydrogen by volume at dierent equivalence

ratios

O2 N2 CH4 H2

1.5 0.1768 0.6672 0.1248 0.0312

1.4 0.1787 0.6742 0.1177 0.0294

1.3 0.1806 0.6813 0.1105 0.0276

1.2 0.1825 0.6886 0.1031 0.0258

1.1 0.1845 0.6961 0.0955 0.0239

1 0.1865 0.7038 0.0878 0.0219

0.95 0.1876 0.7076 0.0838 0.0210

0.9 0.1886 0.7116 0.0799 0.0200

0.85 0.1896 0.7155 0.0759 0.0190

0.8 0.1907 0.7195 0.0718 0.0179

0.7 0.1929 0.7277 0.0635 0.0159

0.6 0.1951 0.7361 0.0551 0.0138

0.5 0.1974 0.7446 0.0464 0.0116

Table 4

Unreacted fueloxidizer composition with addition of water elec-

trolysis products addition (10%) at dierent equivalence ratios

O2 N2 CH4 H2

1.5 0.1824 0.6696 0.1331 0.0147

1.4 0.1842 0.6763 0.1254 0.0139

1.3 0.1860 0.6831 0.1176 0.0130

1.2 0.1879 0.6900 0.1097 0.0121

1.1 0.1899 0.6971 0.1016 0.0112

1 0.1918 0.7043 0.0933 0.0103

0.9 0.1938 0.7117 0.0848 0.00940.8 0.1959 0.7193 0.0762 0.0084

0.7 0.1980 0.7270 0.0674 0.0074

0.6 0.2001 0.7348 0.0584 0.0064

0.5 0.2023 0.7429 0.0492 0.0054

at 0 distance). Values of laminar ame speed S0u , reported

in the literature have been characterized by substantial scat-

ter [25]. This scatter has been attributed to the fact that no

experiments can directly generate an ideal one-dimensional,

planar, adiabatic, steady, unstrained, laminar ame for which

S

0

u is dened. However, three recent and promising resultshave been chosen for comparison [26 28]. Fig. 1 illustrates

that the ame speed simulated by GRI is equal to or higher

than the measured results. This may be a consequence of

tuning the GRI mechanism using the experimental results

from earlier publications where the ame speed was mea-

sured to be higher [28]. However, as shown in Fig. 1, sim-

ulated results are in good agreement with Gu et al.s results

[28] in the lean side (up to equivalence ratio = 1:0). This

measurement set is approximately 10% lower than simula-

tion on the rich side of the curve. However, the rich side

simulations are in good agreement with Van Maarens data

[27], which gives lower than the simulated values for the

lean side. This can be explained by the stretch levels of dif-

Fig. 1. Simulated and measured [2628] laminar ame speeds of

methane=air mixtures.

Fig. 2. Eects of the hydrogen (10 and 20%) and hydrogen=oxygen

(10%) addition on laminar ame speeds at dierent equivalence

ratio methane=air mixtures.

ferent measuring methods and the strong relation between

the level of stretch and ame velocity for low Lewis number

mixtures. Lean methane mixtures are more stoichiometric at

the ame, leading to enhanced burning intensity [31].

The leanest combustible 1 methane=air mixture has been

predicted to be =0:55 with this solution method. This value

is also in good agreement with Zebatakiss [32] measured

value of = 0:54.

Flame speed predictions for methane=air combustion with

H2 and H2 + O2 addition can be seen in Fig. 2. Although

hydrogen has a ame speed seven times higher than

methane, adding 10% hydrogen increases the ame speed

of the mixture by only 8% at = 1:0. Adding 20% H2increases the ame speed by a maximum of 15% at the

stoichiometric condition, whereas a 13% higher levels

in ame speed were predicted with the addition of 10%

H2 + O2. The percentage increase in ame speed due to

1 Although the ammability limit is dened as the leanest fuel

oxidizer mixture ratio beyond which no ame will propagate [30],

in this study it is predicted as the leanest mixture that results in

temperature increase.

7/28/2019 npsAE78

4/9


Fig. 3. Temperature prole of freely propagating premixed laminar

ames of dierent stoichiometric fuel mixtures.

Fig. 4. The eects of dierent additives on nal ame temperature

of freely propagating premixed laminar ame on dierent equiva-

lence ratios.

H2 or H2 + O2 addition is independent of the equivalence

ratio. The leanest ammable mixture for a freely prop-

agating laminar methane=air ame was predicted to be

= 0:55. This was improved to = 0:54 with the ad-

dition of 10% hydrogen. The addition of 20% hydrogen

produced no further improvement in lean ammability limit

( = 0:54). Results from the addition of 10% hydrogenwith accompanying oxygen into methane=air combustion

systems improved the lean ammability limit to = 0 :52.

The reason that the addition of oxygen leads to a further

increase in ame speed and lean ammability limit may be

explained by the increase in the oxygen and methane mole

fraction in the unburnt mixture compared with methane or

methane=hydrogen mixtures of the same equivalence ratio.

Temperature proles of dierent mixtures for the whole

ame area are illustrated in Fig. 3. Although all mixtures

appear to have similar temperature proles, the nal tem-

peratures (temperatures at the end of the computational

domain) vary for dierent mixtures as seen in Fig. 4.

Although hydrogen has a higher ame temperature com-

Fig. 5. The eects of dierent additives on nal carbon monoxide

concentrations.

Fig. 6. The eects of dierent additives on nal NO concentrations.

pared with methane, the ame temperature of the mix-

ture was increased by less than 1% even with the ad-

dition of 20% H2. The addition of oxygen into these

mixtures resulted in a further increase in nal ame

temperature of 1%. These increases are partially due

to the fact that the added oxygen resulted in less air

being added to maintain the same stoichiometry. The use

of oxygen instead of air at the same stoichiometry means

that less inert nitrogen is available to absorb heat in the

reaction, resulting in a higher temperature.

The carbon monoxide concentrations have been compared

for dierent mixtures in Fig. 5. The addition of hydrogencauses the overall carbon to hydrogen ratio of the mixture

to decrease (a pure hydrogen ame produces no CO). As a

result, CO concentrations for the hydrogen added mixtures

decreased. The decrease in CO as compared to methane was

not as great when oxygen was added to the unburnt mixture

due to the higher methane mole fraction. Dierences in CO

concentrations for all lean mixtures were negligibly small,

due to the low CO concentrations found at these equivalence

ratios.

The eects of hydrogen and oxygen addition on NO

concentrations for dierent equivalence ratio methane=air

mixtures are shown in Fig. 6. High temperatures and high

oxygen concentrations result in high NO formation rates

7/28/2019 npsAE78

5/9


Fig. 7. The eects of temperature and oxygen concentration on NO production rate for stoichiometric mixtures ( = 1) (a)

methane=air + hydrogen (b) methane=air + hydrogen + oxygen.

[29]. With hydrogen=methane mixtures, the slight increase in

temperature due to addition of H2 is compensated by the

decrease in oxygen concentration, leading to lower NO

concentrations in lean mixtures. The addition of oxygen

causes the mixture to have both an increase in oxygen con-centration and an increase in adiabatic ame temperature

leading to higher NO concentrations for those mixtures

near stoichiometry. However, for lean mixtures, dierences

in NO emissions are very small.

Figs. 7 and 8 illustrate the reasons for dierent emission

behaviors in dierent mixtures. In stoichiometric mixtures

( = 1), which have maximum total NO levels, an increase

in NO starts with an increase in temperature (0.05 cm)

but in the region that has higher oxygen levels (0.05 0.07

cm) no signicant NO production was observed because

the temperature was low. In Fig. 7, dNO=dt for hydro-

gen and hydrogen=oxygen added mixtures start to increase

as the temperatures are increased (0.07 cm). However,

dierences in NO production take place near the highest

temperature region (0.10 cm). Dierences in NO produc-

tion rate diverge, as the temperature levels are dierent. In

contrast, for lean mixtures (Fig. 8) NO production begins to

dier in the region that has relatively high oxygen concentra-tion dierences and relatively small temperature dierences

(0.7 cm). However, the NO production rates are similar in

regions where the temperature prole is dierent, such as

at 0.2 cm.

As can be seen in Fig. 9, the history of NO levels and

NO production rates are dierent for dierent equivalence

ratios. NO levels for lean mixtures increase up to a

maximum level within a certain distance but remain nearly

constant over the rest of the computational domain. But for

stoichiometric mixtures, increases in NO continue down-

stream till the end of the computational domain. To explain

the dierences in NO production, Fig. 10 is helpful. The

major reactions for NO production have been determined by

7/28/2019 npsAE78

6/9


Fig. 8. The eects of temperature and oxygen concentration on NO production rate for lean mixtures ( = 0:6) (a) methane=air + hydrogen

(b) methane=air + hydrogen + oxygen.

reaction rate parameters and instantaneous concentrations

of reactants for all NO producing reactions. Not surpris-

ingly, the three most common reactions are the well-known

Zeldovich mechanism [29]:

O + N2 NO + N ; (1)

N + O2 NO + O ; (2)

N + OH NO + H : (3)

In dierent mixtures and at dierent equivalence ratios,

reactions responsible for the major NO production vary. For

lean mixtures (c and d), rates of all three reactions are sim-

ilar and reaction (2) has the maximum rate. This might be

the reason for oxygen concentration dependence of NO rates

for lean mixtures. For hydrogen added stoichiometric mix-

tures (a), reaction (3) has the maximum rate starting with the

maximum temperature and up to the end of the ame front.

However, for oxygen=hydrogen added stoichiometric mix-

tures (b), all three reactions have their maximum value at

dierent positions on the ame and have a similar non-zero

value downstream of the reacting front.Although NOx emissions are the total of NO and NO2,

as illustrated in Fig. 11, the nal NO2 concentrations for

all mixtures and all equivalence ratios were predicted to

be less than 1% of the nal NO concentrations. Also, NO2concentrations show similar trends as NO concentrations in

terms of H2 eects (cf. Fig. 11 with Fig. 6).

4. Conclusions

Hydrogen and oxygen have been proposed as additives

to methane-fueled combustion systems in order to improve

7/28/2019 npsAE78

7/9


Fig. 9. NO concentrations and NO production rates of lean and stoichiometric mixtures of methane=hydrogen=air andmethane=hydrogen=oxygen=air with respect to the ame distance.

pollutant emissions and thermal eciency. However, some

theoretical studies about kinetic behavior of these sys-

tems are essential to predict the possible benets and

to reduce drawbacks. In this study, the kinetics of hy-

drogen and oxygen addition eects on basic combustion

properties of methane laminar premixed ames were

investigated.

It has been found that the addition of 10 or 20% hydro-

gen to methane=air laminar premixed ames did not signi-

cantly improve the lean ammability limits. The maximum

increase in lean ammability limit was 2% which occurred

with 20% H2 addition. On the other hand, the addition of

10% hydrogen with oxygen in a H2 : O2 ratio of 2 : 1 resulted

in a 5% increase in lean ammability limit. The tempera-

ture proles and concentrations of pollutant species (NO,

NO2, and CO) for methane=air with 10 or 20% H2 mixtures

were predicted to be similar to the proles for methane =air

mixtures.

The addition of 10% H2 + O2 resulted in as much im-

provement in ame speed as the addition of 20% H2.

7/28/2019 npsAE78

8/9


Fig. 10. The eects of the dierent reactions on NO production for lean and stoichiometric mixtures.

Temperature proles of oxygen added mixtures were

predicted to be higher at all equivalence ratios. Car-

bon monoxide and NOx concentrations of oxygen

added mixtures are also higher than the 10 or 20% H2mixtures.

In summary, the addition of hydrogen and oxygen was

predicted to be more benecial than the addition of pure

hydrogen in terms of ame speed, temperature, lean

ammability limit, and CO concentrations. Increases in

NO concentrations were predicted to be higher with the

addition of hydrogen and oxygen. But it was shown

that these eects could be compensated by the exten-

sion in lean ammability limit. It is also clear that uti-

lizing hydrogen and oxygen as additives in practical

combustion systems may result in higher power outputs

because of the increase in fuel concentration in the mix-

ture compared with methane=air or methane=air + H2

mixtures.

7/28/2019 npsAE78

9/9


Fig. 11. The eects of dierent additives on nal NO2 concentra-

tions.

Acknowledgements

This project was partially sponsored by the Natural

Sciences and Engineering Research Council of Canada

(NSERC).

References

[1] Gold T. Earth outgassing of methane. In: McGeer P, Durbin

E, editors. Methane fuel for the future. New York: Plenum

Press, 1982.

[2] Beck NJ. Natural gas a rational approach to clean air.

SAE Paper 902228, 1990.

[3] Eghbali B. Natural gas a vehicular fuel. SAE Paper 841159,

1984.[4] Fotache CG, Kreutz TG, Law CK. Ignition of

hydrogen-enriched methane by heated air. Combust Flame

1998;112:52232.

[5] Andrews GE, Bradley D. The burning velocity of methane

air mixtures. Combust Flame 1972;18:13353.

[6] Cattelan A, Wallace J. Exhaust emission and energy

consumption eects from hydrogen supplementation of

natural gas. SAE Paper 952497, 1995.

[7] Hoekstra LH, Van Blarigan P, Mulligan N. NOx emissions

and eciency of hydrogen, natural gas, and hydrogen=natural

gas blended fuels. SAE Paper 961103, 1996.

[8] Bell SR, Gupta M. Extension of the lean operating limit for

natural gas fueling of a spark ignited engine using hydrogen

blending. Combust Sci Tech 1997;123:23 48.[9] Fulton J, Lynch F, Marinara R, Wilson B. Hydrogen for

reducing emissions from alternative fuel vehicles. SAE Paper

931813, 1993.

[10] Gauducheau JL, Denet B, Searby G. A numerical study of

lean CH4=H2=air premixed ames at high pressure. Combust

Sci Tech 1998;137:8199.

[11] Karbasi M, Wierzba I. The eects of hydrogen addition

on the stability limits of methane jet diusion ames. Int

J Hydrogen Energy 1998;23(2):123 9.

[12] Karim GA, Wierzba I, Al-Alousi Y. Methane hydrogen

mixtures as fuels. Int J Hydrogen Energy 1996;21(7):

62531.

[13] Raman V, Hansel J, Kielian D, Lynch F, Ragazzi R, Wilson

B. Hythane, a status report. 26th International Symposium on

Automotive Technology and Automation, Aachen, Germany,

1317 September 1993.

[14] MacDonald JS. Evaluation of the hydrogen supplemented

fuel concept with an experimental multi-cylinder engine.

SAE Paper 760101, 1976.

[15] Nagalingam B, Duebel K, Schmillen K. Performance study

using natural gas, hydrogen supplemented natural gas and

hydrogen in AVL research engine. Int J Hydrogen Energy

1983;8(9):71520.

[16] Swain MR, Yusuf MJ, D ulger Z, Swain MN. The eects

of hydrogen addition on natural gas engine operation. SAE

Paper 932775, 1993.

[17] Yu G, Law CK, Wu CK. Laminar ame speeds of

hydrocarbon+air mixtures with hydrogen addition. Combust

Flame 1986;63:339 47.

[18] Jamal Y, Wyszynski ML. On-board generation of

hydrogen-rich gaseous fuels a review. Int J Hydrogen

Energy 1994;19(7):55772.

[19] Wagner T, Jamal Y, Wyszynski ML. Advantages of

fractional addition of hydrogen to internal combustionengines by exhaust gas fuel reforming. HYPOTHESIS

Conference, Cassino-Gaeta, Italy, 2629 June 1995.

[20] Bade Shrestha SO, Karim GA. Hydrogen as an additive to

methane for spark ignition engine application. Int J Hydrogen

Energy 1999;24:57786.

[21] Bade Shresha SO, Karim GA. An investigation of the

addition of dissociated water products to a gas fueled spark

ignition engine. SAE Paper 1999-01-3516, 1999.

[22] Kee RJ, Rupley FM, Miller JA, Coltrin ME, Grcar JF,

Meeks E, Moat HK, Lutz AE, Dixon-Lewis G, Smooke

MD, Warnatz J, Evans GH, Larson RS, Mitchell RE, Petzold

LR, Reynolds WC, Caracotsios M, Stewart WE, Glarborg P.

CHEMKIN collection, release 3.5. San Diego, CA: Reaction

Design, Inc., 1999.[23] Kee RJ, Rupley FM, Meeks E, Miller JA. CHEMKIN III:

a FORTRAN chemical kinetics package for the analysis of

gas-phase chemical and plasma kinetics. Sandia National

Laboratories Report 1996, SAND 96-8216.

[24] Smith GP, Golden DM, Frenklach M, Moriarty NW,

Eiteneer B, Goldenberg M, Bowman CT, Hanson R, Song

S, Gardiner WC, Lissianski V, Qin Z. GRI-Mech 3.5,

www.me.berkeley.edu/gri mech/.

[25] Egolfopoulos FN, Cho P, Law CK. Laminar ame speeds of

methaneair mixtures under reduced and elevated pressures.

Combust Flame 1989;76:37591.

[26] VanMaaren A, Thung DS, DeGoey LPH. Measurement

of ame temperature and adiabatic burning velocity of

methane=air mixtures. Combust Sci Tech 1994;96:32744.[27] Vagelopoulos CN, Egolfopoulos FN. Direct experimental

determination of laminar ame speeds. Twenty-Seventh

Symposium (International) on Combustion 1998. p. 513.

[28] Gu XJ, Haq MZ, Lawes M, Wooley R. Laminar burning

velocity and Markstein lengths of methaneair mixtures.

Combust Flame 2000;121:4158.

[29] Heywood JB. Internal combustion engine fundamentals. New

York: McGraw-Hill, 1988.

[30] Glassman I. Combustion. San Diego: Academic Press, 1996.

[31] Law CK. Dynamics of stretched ames. Twenty-Second

Symposium (International) on Combustion. The Combustion

Institute, 1988. p. 1381402.

[32] Zebatakis MG. Bulletin US Bureau of Mines No. 627,

1965.

Documents

npsAE78