An experimental and kinetic modeling study of the autoignition of α-methylnaphthalene/air and α-methylnaphthalene/n-decane/air mixtures at elevated pressures

Wang, Haowei; Warner, Steven J.; Oehlschlaeger, Matthew A.; Bounaceur, Roda; Biet, Joffrey; Glaude, Pierre‐Alexandre; Battin‐Leclerc, Frédérique

doi:10.1016/j.combustflame.2010.04.007

Cited by 69 publications

(84 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Venot et al (2015), it was shown that a more sophisticated chemical scheme including species with up to six carbon atoms produces comparable results, and that the simpler scheme can reliably model atmospheres with C/O ratios above 1. The scheme has been developed with combustion specialists and validated by experiments conducted in a wide range of temperatures (300-2500 K) and pressures (0.01-100 bar; e.g., Battin-Leclerc et al 2006;Bounaceur et al 2007Bounaceur et al , 2010Anderlohr et al 2010;Wang et al 2010).…”

Section: Ab Initio Chemical Simulationsmentioning

confidence: 99%

Detection of an Atmosphere Around the Super-Earth 55 Cancri E

Tsiaras

Rocchetto

Waldmann

et al. 2016

ApJ

251

238

View full text Add to dashboard Cite

We report the analysis of two new spectroscopic observations in the near-infrared of the super-Earth 55 Cancri e, obtained with the WFC3 camera on board the Hubble Space Telescope. 55 Cancri e orbits so close to its parent star that temperatures much higher than 2000 K are expected on its surface. Given the brightness of 55 Cancri, the observations were obtained in scanning mode, adopting a very long scanning length and a very high scanning speed. We use our specialized pipeline to take into account systematics introduced by these observational parameters when coupled with the geometrical distortions of the instrument. We measure the transit depth per wavelength channel with an average relative uncertainty of 22 ppm per visit and find modulations that depart from a straight line model with a 6σ confidence level. These results suggest that 55 Cancri e is surrounded by an atmosphere, which is probably hydrogen-rich. Our fully Bayesian spectral retrieval code,  -REx, has identified HCN to be the most likely molecular candidate able to explain the features at 1.42 and 1.54 μm. While additional spectroscopic observations in a broader wavelength range in the infrared will be needed to confirm the HCN detection, we discuss here the implications of such a result. Our chemical model, developed with combustion specialists, indicates that relatively high mixing ratios of HCN may be caused by a high C/O ratio. This result suggests this super-Earth is a carbon-rich environment even more exotic than previously thought.

show abstract

Section: Ab Initio Chemical Simulationsmentioning

confidence: 99%

Detection of an Atmosphere Around the Super-Earth 55 Cancri E

Tsiaras

Rocchetto

Waldmann

et al. 2016

ApJ

251

238

View full text Add to dashboard Cite

show abstract

“…Battin-Leclerc et al 2006;Bounaceur et al 2007;Anderlohr et al 2010;Bounaceur et al 2010;Wang et al 2010). Obviously, it is not possible to describe all these validations in detail, but we can mention, for instance, the very recent work of Dirrenberger et al (2011) who has studied the laminar burning velocity of several mixtures including air, hydrogen, and components of natural gas experimentally and modeled it with success.…”

Section: -C 2 Reaction Basementioning

confidence: 99%

A chemical model for the atmosphere of hot Jupiters

Venot

Hébrard

Agúndez

et al. 2012

A&A

228

560

View full text Add to dashboard Cite

Context. The atmosphere of hot Jupiters can be probed by primary transit and secondary eclipse spectroscopy. Owing to the intense UV irradiation, mixing, and circulation, their chemical composition is maintained out of equilibrium and must be modeled with kinetic models. Aims. Our purpose is to release a chemical network and the associated rate coefficients, developed for the temperature and pressure range relevant to hot Jupiters atmospheres. Using this network, we study the vertical atmospheric composition of the two hot Jupiters (HD 209458b and HD 189733b) with a model that includes photolyses and vertical mixing, and we produce synthetic spectra. Methods. The chemical scheme has been derived from applied combustion models that were methodically validated over a range of temperatures and pressures typical of the atmospheric layers influencing the observations of hot Jupiters. We compared the predictions obtained from this scheme with equilibrium calculations, with different schemes available in the literature that contain N-bearing species, and with previously published photochemical models. Results. Compared to other chemical schemes that were not subjected to the same systematic validation, we find significant differences whenever nonequilibrium processes take place (photodissociations or vertical mixing). The deviations from the equilibrium, hence the sensitivity to the network, are larger for HD 189733b, since we assume a cooler atmosphere than for HD 209458b. We found that the abundances of NH 3 and HCN can vary by two orders of magnitude depending on the network, demonstrating the importance of comprehensive experimental validation. A spectral feature of NH 3 at 10.5 μm is sensitive to these abundance variations and thus to the chemical scheme.Conclusions. Due to the influence of the kinetics, we recommend using a validated scheme to model the chemistry of exoplanet atmospheres. The network we release is robust for temperatures within 300-2500 K and pressures from 10 mbar up to a few hundred bars, for species made of C, H, O, and N. It is validated for species up to 2 carbon atoms and for the main nitrogen species (NH 3 , HCN, N 2 , NO x ). Although the influence of the kinetic scheme on the hot Jupiters spectra remains within the current observational error bars (with the exception of NH 3 ), it will become more important for atmospheres that are cooler or subjected to higher UV fluxes, because they depart more from equilibrium.

show abstract

“…The MCE had much lower mixing energy than the CVB which would tend to increase the ignition delay, but the MCE experiments were conducted with higher ignition quality fuel than the CVB which would tend to decrease the ignition delay. Based on the lower injection velocities and effective mixing rates in the MCE along with a larger injector hole size, the MCE had a higher mean equivalence ratio during the ignition event than the CVB which would tend to shorten the ignition delay near 1000 K at moderate pressures for nheptane, iso-cetane, and α-methylnapthalene [2,3,24]. Last, the higher cetane number of the fuel used in the MCE should lead to a shorter ignition delay, though the higher ignition pressure associated with the CVB should decrease the ignition delay difference.…”

Section: Figure 9 Comparison Of Jp-8 Ignition Behavior In the Avl 52mentioning

confidence: 98%

“…Such studies have targeted aviation applications where (1) combustor pressures are low in comparison to diesel engines, (2) nozzle sizes are much larger than typical heavy-duty diesel engines, and (3) injection pressures are an order of magnitude less than today's light or heavy-duty diesel engines. Such efforts have included assessing surrogate pure hydrocarbons that represent JP-8 low and high temperature ignition behavior, laminar flame speed, and evaporation characteristics under pre-ignition pressures typically less than 25 bar [1,2,3,4,5,6,7,8,9,10]. Extrapolation of such low pressure studies toward diesel engine type pre-ignition conditions is difficult since ignition chemistry tends to vary non-linearly with pressure.…”

Section: Introductionmentioning

confidence: 99%

On the Ignition Behavior of JP-8 in Military Relevant Diesel Engines

Schihl¹,

Hoogterp-Decker²

2011

SAE Int. J. Engines

View full text Add to dashboard Cite

U.S. Army ground vehicles predominately use JP-8 as the energy source for ground vehicles based on the 'one fuel forward policy'. Though this policy was enacted almost twenty years ago, there exists little fundamental JP-8 combustion knowledge at diesel engine type boundary conditions. Nevertheless, current U.S. Army ground vehicles predominately use commercial off-the-shelf or modified commercial diesel engines as the prime mover. Unique military engines are typically utilized when commercial products do not meet the mobility and propulsion system packaging requirements of the particular ground vehicle in question. In either case, such engines have been traditionally calibrated using North American diesel fuel (DF-2) and overall engine performance degradation while operating on Jet Propellant 8 (JP-8) wasn't given much consideration since any such associated power loss due to the lower volumetric energy density was not an issue for most applications at then targeted climatic conditions. It is becoming more apparent that current and future commercial diesel engine combustion system strategies will be adversely affected by use of JP-8 in comparison to DF-2 due to combustion affecting chemical and physical property differences of 'out laying' global JP-8 samples that are problematic under largely premixed combustion strategies. One important example is ignition quality where the mean cetane index for JP-8 utilized by the U.S. Army during the last five years has been typically in the 43 to 44 range, but the variance has been relatively large depending on the particular supply source with worst case scenarios exhibiting values near 30. Similar variances have been observed with other key properties such as distillation and viscosity.To date, there has been little research performed on assessing ignition behavior differences between a mean physical and chemical property JP-8 and DF-2. The objective of this submission is to study and document JP-8 autoignition characteristics under diesel engine-like thermodynamic conditions in order to provide information that might be useful in generating JP-8 ignition models. This effort includes recent ignition data from a single cylinder diesel engine, a production multi-cylinder diesel engine, a shock tube, and a constant volume bomb.

show abstract

An experimental and kinetic modeling study of the autoignition of α-methylnaphthalene/air and α-methylnaphthalene/n-decane/air mixtures at elevated pressures

Cited by 69 publications

References 42 publications

Detection of an Atmosphere Around the Super-Earth 55 Cancri E

Detection of an Atmosphere Around the Super-Earth 55 Cancri E

A chemical model for the atmosphere of hot Jupiters

On the Ignition Behavior of JP-8 in Military Relevant Diesel Engines

Contact Info

Product

Resources

About