Match!

Sub-millimeter sized methyl butanoate droplet combustion: Microgravity experiments and detailed numerical modeling

Published on Jan 1, 2013
· DOI :10.1016/j.proci.2012.07.074
Tanvir Farouk18
Estimated H-index: 18
(Princeton University),
Yu Cheng Liu11
Estimated H-index: 11
(Cornell University)
+ 2 AuthorsFrederick L. Dryer68
Estimated H-index: 68
(Princeton University)
Abstract
Abstract Combustion characteristics of isolated sub-millimeter sized methyl butanoate (MB) droplets are studied at low gravity (10 −4  m/s 2 ) in a 1.2 s drop tower. In the experiments, droplets were grown and deployed onto the intersection of two 14 μm silicon carbide fibers in a cross-string arrangement and exposed to symmetrically placed spark ignition sources. The initial droplet diameter was fixed at 0.54 ± 0.01 mm, and experiments were carried out in room temperature air at atmospheric pressure. Detailed measurements of the evolution of droplet diameter, flame standoff ratio and burning rate are reported. The experimental results are compared against predictions from a comprehensive time-dependent, sphero-symmetric droplet combustion simulation that includes detailed gas phase chemical kinetics, spectrally resolved radiative heat transfer, multi-component diffusive transport, full thermal property variations and tether fiber perturbation effects. The predicted combustion characteristics of MB are also compared with n -heptane droplets of nearly identical sizes over a range of oxygen concentrations. The results show that predicted burning histories, burning rates and flame standoff ratios are in excellent agreement with the measurements. The average burning rates and flame temperatures for both fuels were found to be similar even though the heat of combustion of n- heptane is higher by a factor of ∼1.6. However, the average flame standoff ratio for MB was found to be significantly smaller than for n -heptane, due to the presence of additional oxygen atoms in the parent fuel. Important differences in the diffusion flame chemistries of the two fuels are also discussed.
  • References (20)
  • Citations (27)
📖 Papers frequently viewed together
70 Citations
16 Citations
29 Citations
78% of Scinapse members use related papers. After signing in, all features are FREE.
References20
Newest
#1Pascal Diévart (Princeton University)H-Index: 15
#2Sang Hee Won (Princeton University)H-Index: 30
Last. Yiguang Ju (Princeton University)H-Index: 57
view all 5 authors...
Abstract A detailed kinetic model for the oxidation of the biodiesel surrogate, methyl decanoate, has been developed and tested against a broad range of experimental data. The methyl decanoate model consists of both low and high temperature oxidation chemistry. It has been constructed strictly through the extension of the chemical kinetic and thermochemical parameters used to describe the oxidation of the better-understood small methyl ester, methyl butanoate. The constructed model is tested in ...
61 CitationsSource
#1Stephen Dooley (Princeton University)H-Index: 24
#2Mruthunjaya Uddi (Princeton University)H-Index: 11
Last. Yiguang Ju (Princeton University)H-Index: 57
view all 5 authors...
Abstract The extinction limits of methyl butanoate, n-heptane, and methyl butanoate/n-heptane diffusion flames have been measured as a function of fuel mole fraction with nitrogen dilution in counterflow with air. On a mole fraction basis, methyl butanoate diffusion flames are observed to have a much lower extinction strain rate than n-heptane diffusion flames and the extinction strain rate of n-heptane/methyl butanoate diffusion flames is observed to increase significantly as the n-heptane frac...
29 CitationsSource
#1Abhijeet Raj (KAUST: King Abdullah University of Science and Technology)H-Index: 20
#2Iran D. Charry Prada (KAUST: King Abdullah University of Science and Technology)H-Index: 2
Last. Suk Ho Chung (KAUST: King Abdullah University of Science and Technology)H-Index: 42
view all 4 authors...
Abstract This work aims to develop a reaction mechanism for gasoline surrogate fuels (n-heptane, iso-octane and toluene) with an emphasis on the formation of large polycyclic aromatic hydrocarbons (PAHs). Starting from an existing base mechanism for gasoline surrogate fuels with the largest chemical species being pyrene (C 16 H 10 ), this new mechanism is generated by adding PAH sub-mechanisms to account for the formation and growth of PAHs up to coronene (C 24 H 12 ). The density functional the...
93 CitationsSource
#1Yu Cheng Liu (Cornell University)H-Index: 11
#2C. Thomas Avedisian (Cornell University)H-Index: 14
29 CitationsSource
#1Tanvir Farouk (Princeton University)H-Index: 18
#2Frederick L. Dryer (Princeton University)H-Index: 68
Abstract Tethered methanol droplet combustion in carbon dioxide enriched environment is simulated using a transient one-dimensional spherosymmetric droplet combustion model that includes the effects of tethering. A priori numerical predictions are compared against recent experimental data. The numerical predictions compare favorably with the experimental results and show significant effects of tethering on the experimental observations. The presence of a relatively large quartz fiber tether incr...
22 CitationsSource
#1Tanvir Farouk (Princeton University)H-Index: 18
#2Frederick L. Dryer (Princeton University)H-Index: 68
Droplets tethering on fibers has become a well established technique for conducting droplet combustion experiments in microgravity conditions. The effects of these supporting fibers are frequently assumed to be negligible and are not considered in the experimental analysis or in numerical simulations. In this work, the effect of supporting fibers on the characteristics of microgravity droplet combustion has been investigated numerically; a priori predictions have then been compared with publishe...
32 CitationsSource
#1Olivier Herbinet (Nancy-Université)H-Index: 33
#2William J. Pitz (LLNL: Lawrence Livermore National Laboratory)H-Index: 60
Last. Charles K. Westbrook (LLNL: Lawrence Livermore National Laboratory)H-Index: 63
view all 3 authors...
Detailed chemical kinetic mechanisms were developed and used to study the oxidation of two large unsaturated esters: methyl-5-decenoate and methyl-9-decenoate. These models were built from a previous methyl decanoate mechanism and were compared with rapeseed oil methyl esters oxidation experiments in a jet-stirred reactor. A comparative study of the reactivity of these three oxygenated compounds was performed and the differences in the distribution of the products of the reaction were highlighte...
229 CitationsSource
#1Marcos Chaos (Princeton University)H-Index: 22
#2Andrei F. Kazakov (Princeton University)H-Index: 21
Last. Frederick L. Dryer (Princeton University)H-Index: 68
view all 4 authors...
A chemical kinetic mechanism has been developed to describe the high-temperature oxidation and pyrolysis of n-heptane, iso-octane, and their mixtures. An approach previously developed by this laboratory was used here to partially reduce the mechanism while maintaining a desired level of detailed reaction information. The relevant mechanism involves 107 species undergoing 723 reactions and has been validated against an extensive set of experimental data gathered from the literature that includes ...
112 CitationsSource
#1S. Gaïl (U of T: University of Toronto)H-Index: 3
#2Murray J. Thomson (U of T: University of Toronto)H-Index: 34
Last. Frederick L. Dryer (Princeton University)H-Index: 68
view all 8 authors...
A detailed chemical kinetic model has been used to study methyl butanoate (a model compound for biodiesel fuels) oxidation over a wide range of conditions. New experimental results obtained in a jet stirred reactor (JSR) at 0.101 MPa, Φ = 1.13 and 800 < T (K) < 1350 were obtained and used to test and modify an earlier model. In addition, new experimental data generated in an opposed-flow diffusion flame at 0.101 MPa and in the Princeton variable pressure flow reactor (VPFR) at 1.266 MPa, 0.35 < ...
158 CitationsSource
#1S.M. Sarathy (U of T: University of Toronto)H-Index: 8
#2S. Gaïl (U of T: University of Toronto)H-Index: 3
Last. Philippe Dagaut (CNRS: Centre national de la recherche scientifique)H-Index: 51
view all 5 authors...
Abstract Biodiesel fuels, made up primarily of fatty acid methyl esters (FAME), are advantageous because they are renewable and generally have lower pollutant emissions. In order to study in detail the effect of the FAME molecular structure on the combustion chemistry, a saturated (i.e., methyl butanoate) and an unsaturated (i.e., methyl crotonate) C 4 FAME were oxidized in an opposed flow diffusion flame and a jet stirred reactor. Some consistent trends were seen in both experiments. Both fuels...
103 CitationsSource
Cited By27
Newest
#1Shion Ando (UTokyo: University of Tokyo)
#2Yuxiang Wu (UTokyo: University of Tokyo)
Last. Mitsuhiro Tsue (UTokyo: University of Tokyo)H-Index: 15
view all 4 authors...
Abstract Droplet combustion behavior of degraded and non-degraded fatty acid methyl ester (FAME) were studied under microgravity condition. Accelerated oxidation tests were conducted for methyl laurate (LME) and methyl oleate (OME) as representatives of FAME, and the changes in viscosities and compositions were evaluated. The Rancimat method was employed for oxidizing fuels at 100 °C for 6 or 24 h. The viscosities and compositions were measured with an Ubbelohde viscometer and a gas chromatograp...
Source
#1Hiroshi Nomura (College of Industrial Technology)H-Index: 10
#2Shinji Nakaya (UTokyo: University of Tokyo)H-Index: 8
Last. Mitsuhiro Tsue (UTokyo: University of Tokyo)H-Index: 15
view all 3 authors...
Source
#1Yanlei Shang (Southwest Jiaotong University)H-Index: 2
#2Hongbo Ning (Southwest Jiaotong University)H-Index: 5
Last. Sheng-Nian Luo (Southwest Jiaotong University)H-Index: 18
view all 5 authors...
Methyl pentanoate (MP) was recently proposed as a potential biodiesel surrogate due to its negative temperature coefficient region. To provide a basis for constructing an accurate mechanism, chemical kinetics of H-abstraction from MP by an OH radical are investigated theoretically at 200–2000 K. M06-2X/cc-pVTZ is applied for geometry optimizations and frequency calculations. Given the long alkyl-chain in MP, the multi-structural torsional anharmonicity is characterized by using the dual-level MS...
Source
#1Álvaro Muelas (University of Zaragoza)H-Index: 1
#2Pilar Remacha (University of Zaragoza)H-Index: 1
Last. Javier Ballester (University of Zaragoza)H-Index: 23
view all 3 authors...
Abstract The droplet combustion characteristics of conventional heating oil, UCO biodiesel and their mixtures (10 and 20% biodiesel by volume) were examined in a free-falling droplet combustion facility designed to approach the typical temperature and oxygen conditions around individual droplets in real boiler flames. Moreover, and given the importance of avoiding effects due to gravity or convection in this type of experiments, the quite spherical soot shells recorded (infrequent event in free-...
1 CitationsSource
#1Vasudevan Raghavan (Indian Institute of Technology Madras)H-Index: 14
Understanding the transport processes during evaporation and combustion of isolated liquid fuel droplet is highly important in several applications involving sprays. Comprehensive numerical models assist in carrying out simulations involving interlinked transport processes in liquid and gas phases using proper interface coupling conditions. The predictions from such numerical models reveal flow, temperature and species fields, with which the evaporation, as well as combustion characteristics, ca...
Source
#1Fahd E. Alam (USC: University of South Carolina)H-Index: 4
#2Sang Hee Won (USC: University of South Carolina)H-Index: 3
Last. Tanvir Farouk (USC: University of South Carolina)H-Index: 18
view all 4 authors...
Abstract Cool flame combustion of individual and isolated sub-millimeter sized n -heptane ( n -C 7 H 16 ) and n -decane ( n -C 10 H 22 ) droplets are computationally investigated for atmospheric and higher operating pressure (25 atm) conditions with varying levels of ozone (O 3 ) mole fractions in the surroundings. A sphero-symmetric, one-dimensional, transient, droplet combustion model is utilized, employing reduced versions of detailed chemical kinetic models for the fuel species and an append...
3 CitationsSource
#1Anirudha Ambekar (IITB: Indian Institute of Technology Bombay)H-Index: 4
#2Arindrajit Chowdhury (IITB: Indian Institute of Technology Bombay)H-Index: 11
Abstract The burning rate constant of the droplets of a liquid fuel solely characterized by the thermo-physical properties of the fuel and the oxidizer is an intrinsic characteristic of the fuel. The classical quasi-steady approach enables estimation of such a parameter in a highly idealized scenario with a range of simplifying assumptions. Furthermore, this quasi-steady method requires the knowledge of the thermo-physical properties of the fuel along with the expected adiabatic flame temperatur...
3 CitationsSource
#1Anirudha Ambekar (IITB: Indian Institute of Technology Bombay)H-Index: 4
#2Amit Kumar Maurya (IITB: Indian Institute of Technology Bombay)H-Index: 1
Last. Arindrajit Chowdhury (IITB: Indian Institute of Technology Bombay)H-Index: 11
view all 3 authors...
Abstract An experimental study was conducted on droplet combustion of the monopropellant pure nitromethane (NM) as well as NM blended with methanol. Pure NM droplet combustion was conducted in a quiescent atmosphere of air with the droplets supported at the tip of quartz fibers under normal gravity. Additional experiments were conducted by varying the ambient oxygen mass fractions. The dependence of burning rate constant on initial droplet diameter was determined for pure NM, pure methanol, and ...
4 CitationsSource
#1Alessandro Stagni (Polytechnic University of Milan)H-Index: 9
#2Alberto Cuoci (Polytechnic University of Milan)H-Index: 30
Last. Tiziano Faravelli (Polytechnic University of Milan)H-Index: 45
view all 5 authors...
Abstract The use of isolated droplets as idealized systems is an established practice to get an insight on the physics of combustion, and an optimal test field to verify physical submodels. In this context, this work examines the dynamics of soot formation from the combustion of hydrocarbon liquid fuels in such conditions. A detailed, heterogeneous kinetic mechanism, describing aerosol and particle behavior through a discrete sectional approach is incorporated. The developed 1-dimensional model ...
5 CitationsSource
#1Yuhao Xu (Cornell University)H-Index: 7
#2Michael C. Hicks (Glenn Research Center)H-Index: 8
Last. C. Thomas Avedisian (Cornell University)H-Index: 14
view all 3 authors...
Abstract The burning characteristics of iso -octane droplets in the standard atmosphere are reported over a large range of initial droplet diameters (0.5 mm D o 5 mm) for near one-dimensional droplet flames as promoted by low gravity. A ground-based drop tower and a space-based platform (International Space Station) were used to provide an environment to examine the influence of D o that encompasses regimes where radiation does not have an effect on burning to where it does. For D o K ) was near...
3 CitationsSource