Branding/Logomark minus Citation Combined Shape Icon/Bookmark-empty Icon/Copy Icon/Collection Icon/Close Copy 7 no author result Created with Sketch. Icon/Back Created with Sketch. Match!

Unsteady droplet combustion with fuel thermal expansion

Published on Sep 1, 2018in Combustion and Flame 4.12
· DOI :10.1016/j.combustflame.2018.01.035
Vedha Nayagam13
Estimated H-index: 13
(Case Western Reserve University),
Vedha Nayagam4
Estimated H-index: 4
(Case Western Reserve University)
+ 0 AuthorsForman A. Williams48
Estimated H-index: 48
(UCSD: University of California, San Diego)
Cite
Abstract
Abstract Millimeter-size fuel droplets burning in microgravity show substantial thermal expansion at earlier times in their burning history. Here, we develop a simple model that accounts for thermal expansion of the liquid fuel and compare it against experimental measurements. The results show that excellent agreement with measured droplet-diameter histories throughout the hot-flame period of combustion is obtained when the effect of thermal expansion is included.
  • References (10)
  • Citations (0)
Cite
References10
Newest
Published on Jul 4, 2017in Combustion Theory and Modelling 1.65
Vedha Nayagam4
Estimated H-index: 4
(Case Western Reserve University),
Daniel L. Dietrich13
Estimated H-index: 13
(Glenn Research Center),
Forman A. Williams48
Estimated H-index: 48
(UCSD: University of California, San Diego)
A Burke–Schumann description of three different regimes of combustion of a fuel droplet in an oxidising atmosphere, namely the premixed-flame regime, the partial-burning regime and the diffusion-flame regime, is presented by treating the fuel and oxygen leakage fractions through the flame as known parameters. The analysis shows that the burning-rate constant, the flame-standoff ratio, and the flame temperature in these regimes can be obtained from the classical droplet-burning results by suitabl...
Published on Oct 1, 2014in Microgravity Science and Technology 1.97
Daniel L. Dietrich13
Estimated H-index: 13
(Glenn Research Center),
Vedha Nayagam4
Estimated H-index: 4
(Case Western Reserve University)
+ 9 AuthorsYu Cheng Liu10
Estimated H-index: 10
(Cornell University)
This paper summarizes the first results from isolated droplet combustion experiments performed on the International Space Station (ISS). The long durations of microgravity provided in the ISS enable the measurement of droplet and flame histories over an unprecedented range of conditions. The first experiments were with heptane and methanol as fuels, initial droplet droplet diameters between 1.5 and 5.0 m m, ambient oxygen mole fractions between 0.1 and 0.4, ambient pressures between 0.7 and 3.0 ...
Published on Feb 1, 2014in Combustion and Flame 4.12
Tanvir Farouk17
Estimated H-index: 17
(USC: University of South Carolina),
Frederick L. Dryer66
Estimated H-index: 66
(Princeton University)
Abstract Recent experimentally observed two stage combustion of n -heptane droplets in microgravity is numerically studied. The simulations are conducted with detailed chemistry and transport in order to obtain insight into the features controlling the low temperature second stage burn. Predictions show that the second stage combustion occurs as a result of chemical kinetics associated with classical premixed “ Cool Flame ” phenomena. In contrast to the kinetic interactions responsible for premi...
Published on Dec 1, 2012in Combustion and Flame 4.12
Vedha Nayagam13
Estimated H-index: 13
,
Daniel L. Dietrich13
Estimated H-index: 13
(Glenn Research Center)
+ 2 AuthorsForman A. Williams48
Estimated H-index: 48
(UCSD: University of California, San Diego)
Abstract Experimental observations of anomalous combustion of n-heptane droplets burning in microgravity are reported. Following ignition, a relatively large n-heptane droplet first undergoes radiative extinction, that is, the visible flame ceases to exist because of radiant energy loss. But the droplet continues to experience vigorous vaporization for an extended period according to a quasi-steady droplet-burning law, ending in a secondary extinction at a finite droplet diameter, after which a ...
Published on Jun 1, 2006in Combustion Science and Technology 1.56
Hojat Ghassemi11
Estimated H-index: 11
(KAIST),
Seungwookbaek30
Estimated H-index: 30
(KAIST),
Qasim Sarwar Khan4
Estimated H-index: 4
(KAIST)
The evaporation characteristics of single and multicomponent droplets hanging at the tip of a quartz fiber are studied experimentally at the different environmental conditions under normal gravity. Heptane and Hexadecane are selected as two fuels with different evaporation rates and boiling temperatures. At the first step, the evaporation of single component droplet of both fuels has been examined separately. At the next step the evaporation of several blends of these two fuels, as a binary comp...
Published on Mar 1, 2006in Heat and Mass Transfer 1.55
T. Elperin28
Estimated H-index: 28
(BGU: Ben-Gurion University of the Negev),
Boris Krasovitov9
Estimated H-index: 9
(BGU: Ben-Gurion University of the Negev)
Transient sub-critical droplet evaporation in non-isothermal stagnant gaseous mixtures taking into account the effects of radiation, liquid volumetric expansion and droplet heating is investigated numerically. We obtained equations for Stefan velocity and the rate of change of the droplet radius taking into account liquid volumetric expansion, and derived the boundary conditions taking into account the effect of liquid thermal expansion. It is shown that in the case of sub-critical evaporation n...
Published on Jan 1, 1982in Progress in Energy and Combustion Science 26.47
Chung K. Law77
Estimated H-index: 77
(NU: Northwestern University)
Abstract Recent progress on understanding the fundamental mechanisms governing droplet vaporization and combustion are reviewed. Topics include the classical d 2 -Law and its limitations; the major transient processes of droplet heating and fuel vapor accumulation; effects due to variable transport property assumptions; combustion of multicomponent fuels including the miscible fuel blends, immiscible emulsions, and coal-oil mixtures, finite-rate kinetics leading to ignition and extinction; and d...
Published on Jan 1, 1977in Combustion and Flame 4.12
Chung K. Law77
Estimated H-index: 77
(NU: Northwestern University),
W. A. Sirignano42
Estimated H-index: 42
(Princeton University)
Abstract The spherically-symmetric, thin-flame combustion of a pure component droplet is analyzed by assuming quasi-steady gas-phase processes and conduction being the only heat transfer mechanism within the droplet. Exact numerical, and an approximate analytical, solutions are presented. Results show that droplet heating is the dominant heat utilization mode for the initial 10–20% of the droplet lifetime, during which rapid changes in all combustion characteristics occur; that although unsteadi...
Published on Feb 1, 1976in Combustion and Flame 4.12
Chung K. Law77
Estimated H-index: 77
(Princeton University)
Abstract Unsteady droplet combustion caused by droplet heating is modelled by assuming quasi-steady gas-phase processes and the droplet temperature being spatially uniform but temporally varying. Results show droplet heating is a significant source for the experimentally observed unsteady combustion phenomena of Okajima and Kumagai.
Cited By0
Newest