Match!

Experimental study of the effect of helium/nitrogen concentration and initial droplet diameter on nonane droplet combustion with minimal convection

Published on Jan 1, 2007
· DOI :10.1016/j.proci.2006.08.042
J.H. Bae1
Estimated H-index: 1
(Cornell University),
C.T. Avedisian24
Estimated H-index: 24
(Cornell University)
Cite
Abstract
In this paper, we study the influence of inert concentration and initial droplet diameter on nonane (C9H20) droplet combustion in an environment that promotes spherical droplet flames. The oxygen concentration is fixed while the inert is varied between nitrogen and helium. A range of initial droplet diameters (Do) are examined in each ambient gas: 0.4 mm < Do < 0.8 mm; and an oxidizing ambiance consisting of 30% oxygen (fixed) and 70% inert (fixed), with the inert in turn composed of mixtures of nitrogen and helium in concentrations of 0, 25, 50, 75, and 100% N2. The experiments are carried out at normal atmospheric pressure in a cold ambiance (room temperature) under low gravity to minimize the influence of convection and promote spherical droplet flames. For burning within a helium inert (0% N2), the droplet flames are entirely blue and there is no influence of initial droplet diameter on the local burning rate (K). With increasing dilution by nitrogen, droplet flames show significant yellow luminosity indicating the presence of soot and the individual burning histories show K reducing with increasing Do. The evolution of droplet diameter D(t) is nonlinear for a given Do in the presence of either helium or nitrogen inerts indicating that soot formation has little to do with nonlinear burning. A correlation is presented of the data in the form (D/Do)2(1+e)=1-K′t/Do2(1+e) where the effective burning rate, K′, and e are concentration-dependent. Correlations for these parameters are presented in the paper.
  • References (15)
  • Citations (17)
Cite
References15
Newest
Published on Jan 1, 1985
F. A. Williams1
Estimated H-index: 1
* Summary of Relevant Aspects of Fluid Dynamics and Chemical Kinetics * Rankine-Hugoniot Relations * Diffusion Flames and Droplet Burning * Reactions in Flows with Negligible Molecular Transport * Theory of Laminar Flames * Detonation Phenomena * Combustion of Solid Propellants * Ignition, Extinction, and Flammability Limits * Combustion Instabilities * Theory of Turbulent Flames * Spray Combustion * Flame Attachment and Flame Spread
Published on Jan 1, 2007
Ahmet Yozgatligil8
Estimated H-index: 8
(Drexel University),
Seul-Hyun Park7
Estimated H-index: 7
(Drexel University)
+ 2 AuthorsFrederick L. Dryer66
Estimated H-index: 66
(Princeton University)
Abstract The influence of oxygen (O 2 ) concentration and inert on the sooting and burning behavior of large ethanol droplets under microgravity conditions was investigated through measurements of burning rate, flame temperature, sootshell diameter, and soot volume fraction. The experiments were performed at the NASA Glenn Research Center (GRC) 2.2 s drop tower in Cleveland, OH. Argon (Ar), helium (He), and nitrogen (N 2 ) were used as the inerts and the O 2 concentration was varied between 21% ...
Published on Apr 1, 2004in Combustion and Flame4.12
J.H. Bae2
Estimated H-index: 2
(Cornell University),
C.T. Avedisian24
Estimated H-index: 24
(Cornell University)
Abstract Combustion of stationary JP8 fuel droplets mixed with additives is examined in a low gravity environment to reduce the influence of convection and promote spherical droplet flames. Both qualitative information on flame structure and sooting tendencies and quantitative information on evaporation rates and flame and soot shell diameters are reported. The additives were hexanol (C 6 H 14 O) and a commercial blend of a detergent/dispersant termed “+100” that is widely used as an additive in...
Published on Mar 1, 2003in International Journal of Heat and Mass Transfer4.35
Guangwen Xu8
Estimated H-index: 8
(AIST: National Institute of Advanced Industrial Science and Technology),
Masiki Ikegami9
Estimated H-index: 9
(AIST: National Institute of Advanced Industrial Science and Technology)
+ 5 AuthorsPeter M. Struk11
Estimated H-index: 11
Abstract Isolated droplet burning were conducted in microgravity ambiences of different temperatures to test the initial diameter influence on droplet burning rate that shows a flame scale effect and represents an overall thermal action of flame in balance with heat loss. The coldest ambience examined was room air, which utilized a heater wire to ignite the droplet. All other ambiences hotter than 633 K were acquired through an electrically heated air chamber in a stainless steel can. An inverse...
Published on Feb 1, 2003in Fuel5.13
Guangwen Xu8
Estimated H-index: 8
(AIST: National Institute of Advanced Industrial Science and Technology),
Masiki Ikegami9
Estimated H-index: 9
(AIST: National Institute of Advanced Industrial Science and Technology)
+ 4 AuthorsYasuhiro Takeshita4
Estimated H-index: 4
Abstract Development of gas turbines fueled with light cycle oil (LCO) and oil mixture of LCO and diesel light oil (LO) requires an understanding of the droplet burning and vaporization characteristics of those oils. The present study is devoted to comparing the burning characteristics of isolated fuel droplets composed of an LCO and an LO. The tests were conducted in an atmospheric hot-air chamber preset at 1173 K, and the examined LCO had a lower cetane number but higher volatility and aromati...
Published on Jan 1, 2000
C. Thomas Avedisian14
Estimated H-index: 14
(Cornell University),
Brian J. Callahan1
Estimated H-index: 1
(Cornell University)
In this paper we present new data on the combustion of stationary nonane/hexanol mixture droplets burning in microgravity to promote spherical symmetry. Compositions of 10%, 25%, 40%, 60%, and 80% (volume percent hexanol) were examined in a drop tower to create an environment whereby droplets could burn without a strong influence of buoyancy. The evolution of droplet, soot shell, and flame diameter were measured, and photographs are presented to show sooting trends as composition was varied. Dro...
Published on Feb 1, 1998in Combustion Science and Technology1.56
Kyeong-Ook Lee6
Estimated H-index: 6
(UIC: University of Illinois at Chicago),
Samuel L. Manzello24
Estimated H-index: 24
(UIC: University of Illinois at Chicago),
Mun Young Choi21
Estimated H-index: 21
(UIC: University of Illinois at Chicago)
Abstract The influence of initial droplet diameter on the sooting and burning behavior of isolated droplets under microgravity conditions was investigated by measuring soot volume fraction, ƒv, soot mass, m s, soot and burning rate. Theƒ v, and m s, soot were measured using a full-field light extinction and tomographic inversion technique. The experiments were conducted at the NASA-Lewis 2·2 second droptower in Cleveland, OH. The ƒ v, and m s, soot measurements represent the first quantitative a...
Published on Jan 1, 1998
Anthony J. Marchese23
Estimated H-index: 23
(Princeton University),
Frederick L. Dryer66
Estimated H-index: 66
(Princeton University),
R.O. Colantonio4
Estimated H-index: 4
The results from methanol/water droplet combustion experiments conducted on two separate spacebased investigations are analyzed and compared against the predictions of a detailed numerical model. These two investigations (Fiber Supported Droplet Combustion Investigations 1 and 2) were conducted aboard Space Shuttle Columbia missions STS-73 and STS-94 in November 1995 and July 1997, respectively. In these experiments, pure methanol droplets and methanol/water droplets of 2–7 mm were suspended on ...
Published on Aug 8, 1994
G. S. Jackson1
Estimated H-index: 1
(Cornell University),
C. T. Avedisian1
Estimated H-index: 1
(Cornell University)
The effect of initial droplet diameter on the burning rate of sooting fuels – n-heptane and 1-chloro-octane – was examined experimentally at low gravity. A 1.2s drop tower provided a low gravity environment to minimize buoyancy and achieve spherically symmetric flames for stationary droplets. Free-floating and fibre-supported droplets were burned, and both techniques gave matching results for droplets of similar initial diameter. Burning rate constants for both fuels were measured for a large nu...
Published on Feb 1, 1990in International Journal of Heat and Mass Transfer4.35
B.D. Shaw1
Estimated H-index: 1
(UCSD: University of California, San Diego),
Forman A. Williams48
Estimated H-index: 48
(UCSD: University of California, San Diego)
Abstract Analyses are given for the evolution of liquid-phase mass fraction profiles and temperature during combustion of fuel droplets composed of binary miscible mixtures of low-volatility and high-volatility constituents, with small initial mass fractions of the low-volatility material, or slow introduction of low-volatility material into the liquid phase by absorption from the gas phase. The gas phase is assumed to remain quasisteady and the liquid temperature spatially uniform. The ratio of...
Cited By17
Newest
Published on Dec 1, 2018in AIAA Journal1.95
C. L. Vang (UC Davis: University of California, Davis), B. D. Shaw (UC Davis: University of California, Davis)
Combustion experiments on heptane–hexadecane mixture droplets were conducted onboard the International Space Station. The ambient consisted of oxygen mixed with either helium or nitrogen at 1 atm. Initial droplet diameters were in the 1.7–4.8 mm range with initial heptane mass fractions of 0.95 or 0.80. Because of limitations on resources, only fiber-supported experiments were possible. Vaporization of the more volatile fuel component (heptane) was favored during the droplet combustion process, ...
Published on Aug 1, 2017in Combustion and Flame4.12
Cameron Verwey2
Estimated H-index: 2
(UM: University of Manitoba),
Madjid Birouk16
Estimated H-index: 16
(UM: University of Manitoba)
Abstract This paper presents the results of an experimental investigation of the effect of droplet size on the fuel vaporization process in a turbulent atmosphere at standard ambient conditions. Single droplets of n-heptane and n-decane are formed and evaporated at the intersection point of two micro-fibers placed in the center of a fan-stirred spherical vessel which is maintained at room temperature and pressure. The droplet initial diameter varies in the range between 145 and 730 µm. A control...
Published on Feb 1, 2017in Fuel5.13
Kai Han7
Estimated H-index: 7
(BIT: Beijing Institute of Technology),
Hao Chen2
Estimated H-index: 2
(BIT: Beijing Institute of Technology)
+ 3 AuthorsYuchuan Li3
Estimated H-index: 3
(BIT: Beijing Institute of Technology)
Abstract In this work, the droplet burning characteristics of neat benzyl azides, diesel-benzyl azides blends (10%, 30%, 50% of benzyl azides (wt.)) and diesel fuel were investigated under atmospheric pressure. The ambient temperature around the flat-flame burner is about 1123 K. The initial droplet temperature is about 300 K. The effects of ambient oxygen concentration (14%, 21% and 30%) and initial droplet diameter (∼257 μm and ∼456 μm) on the burning characteristics were also studied. Experim...
Published on Jan 2, 2016in Combustion Science and Technology1.56
Benjamin D. Shaw13
Estimated H-index: 13
(UC Davis: University of California, Davis),
Chang L. Vang1
Estimated H-index: 1
(UC Davis: University of California, Davis)
ABSTRACTReduced gravity combustion experiments were performed aboard the International Space Station with individual methanol and n-heptane droplets that had initial diameters in the 1.2–5.0-mm-size range. Experiments were performed with air-inert mixtures at 0.1 and 0.07 MPa and about 298 K, where the monatomic gases helium and xenon were separately used as the added inert. These two gases have the same thermodynamic properties on a molar basis, but their transport properties are significantly ...
Published on Jan 1, 2015
Zifeng Hong , Jing Zhao2
Estimated H-index: 2
+ 2 AuthorsYanjun Li
It has some significance to study the influences of the droplet radius ratios on spray combustion due to the varying droplet radius ratios among droplets in the actual spray combustion. The volume of fluid (VOF) formulation is applied to model the combustion process of two decane droplets with different radiuses in a hot convective flow and the effects of the droplet ratios on burning rates of two droplets at fixed droplet center spacing are analyzed. The results show: when the burning rates of ...
Published on Nov 1, 2013in Fuel5.13
Kuo-Long Pan13
Estimated H-index: 13
(NTU: National Taiwan University),
Ming-Chun Chiu1
Estimated H-index: 1
(NTU: National Taiwan University)
Abstract Based on a drop tower built in the lab space, an environment of reduced gravity was employed to study the droplet combustion of multi-component fuels, specifically of diesel mixed with alcohol (methanol, ethanol, and 2-propanol) and biodiesel. The falling duration was about 0.68 s and was sufficient for complete burning of a droplet with a diameter as small as 0.5 mm that was suspended at the crossing point of two ultra-thin fibers with a diameter of 2.5 μm. The fibers were made of cera...
Published on Jan 1, 2013
Shinji Nakaya8
Estimated H-index: 8
(UTokyo: University of Tokyo),
Kotaro Fujishima1
Estimated H-index: 1
(UTokyo: University of Tokyo)
+ 2 AuthorsDaisuke Segawa10
Estimated H-index: 10
(OPU: Osaka Prefecture University)
Abstract The burning characteristics of isolated fuel droplets for ethanol, 1-butanol and n -decane were experimentally examined in carbon dioxide-rich or argon-rich environments under microgravity. The ambience consisted of oxygen, nitrogen, carbon dioxide and argon. The concentration of oxygen was fixed to be 21% in volume percentage, and that of carbon dioxide or argon was varied from 0% to 60% in volume percentage. Detailed measurements of the droplet surface areas were conducted using a hig...
Published on Feb 1, 2012in Combustion and Flame4.12
Yu Cheng Liu10
Estimated H-index: 10
(Cornell University),
C. Thomas Avedisian14
Estimated H-index: 14
(Cornell University)
Abstract The droplet burning characteristics of binary blends of iso-octane, n -heptane and toluene were studied in an ambience that minimizes external convection and promotes spherical droplet flames. The results are compared to gasoline (87 octane rating). The initial droplet diameter was fixed at 0.51 ± 0.02 mm and the experiments were carried out in room temperature air. Measurements of the evolution of droplet diameter show that iso-octane, n -heptane and their mixtures have almost identica...
Published on Jan 9, 2012
Yu Cheng Liu10
Estimated H-index: 10
,
Anthony J. Savas5
Estimated H-index: 5
,
C. Thomas Avedisian14
Estimated H-index: 14
This study examines the extent to which three and four component mixtures can replicate the burning characteristics of an aviation fuel, Jet-A (designated by the Air Force as “POSF4658”). The three component mixture (n-decane/iso-octane/toluene with a molar ratio 42.67/33.02/24.31) was previously developed to match the derived cetane number and H/C ratio of Jet-A, whereas the four component mixture (n-dodecane/iso-octane/1,3,5trimethylbenzene/n-propylbenzene with a molar ratio 40.41/29.48/7.28/2...
Published on Jan 1, 2012in Combustion and Flame4.12
Tanvir Farouk17
Estimated H-index: 17
(Princeton University),
Frederick L. Dryer66
Estimated H-index: 66
(Princeton University)
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...