Journal ArticleDOI
An evaluation of actual and simulated smoke properties
TLDR
In this article, the morphology, transport and optical properties of actual and simulated smoke sources were investigated for smoke detection certification in cargo compartments, and the morphology of the smoke from three different flaming fires was compared.Abstract:
Federal regulations require that aircraft cargo compartment smoke detection systems be certified by testing their operation in flight. For safety reasons, only simulated smoke sources are permitted in these certification tests. To provide insight into smoke detection certification in cargo compartments, this research investigates the morphology, transport and optical properties of actual and simulated smoke sources. Experimental data show the morphology of the particulate in smoke from flaming fires is considerably different from simulated smoke. Although the detection of smoldering fires is important as well, only a qualitative assessment and comparison of smoldering sources was possible; therefore, efforts were concentrated on the quantitative comparison of smoke from flaming fires and smoke generators. The particulate for all three different flaming fires was solid with similar morphological properties. Simulated smoke was composed of relatively large liquid droplets, and considerably different size droplets can be produced using a single machine. Transport behavior modeling showed that both the actual and simulated smoke particulates are sufficiently small to follow the overall gas flow. However, actual smoke transport will be buoyancy driven due to the increased temperature, while the simulated smoke temperature is typically low and the release may be momentum driven. The morphology of the actual and simulated smoke were then used to calculate their optical properties. In contrast to the actual smoke from a flaming fire, which is dominated by absorption, all of the extinction for the simulated smoke is due to scattering. This difference could have an impact on detection criteria and hence the alarm time for photoelectic smoke detectors since they alarm based on the scattering properties of the smoke.read more
Citations
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Journal ArticleDOI
Variation of the optical properties of soot as a function of particle mass
TL;DR: In this paper, the authors investigated the size-dependent optical properties of particles produced by a single source, and observed that the absorption cross section and graphitization level of the soot particles increase with the particle mass.
In Situ burning of Arctic marine oil spills: Ignitability of various oil types weathered at different ice conditions. A combined laboratory and field study
TL;DR: In this article, a small laboratory scale burning cell has been constructed to perform a controlled experimental burn on a 100 mL scale (weathered and emulsified oil). This burning cell is a complete unit with cooling water, exhaust system, full temperature control and protection for the operator.
Journal ArticleDOI
Aircraft cargo compartment fire detection and smoke transport modeling
David Blake,Jill M. Suo-Anttila +1 more
TL;DR: In this paper, a transient computational fluid dynamics computer code for the prediction of smoke, heat, and gas species transport in cargo compartments has been developed for the purpose of improving the detection system design and certification process.
Journal ArticleDOI
Modelling of light extinction by soot particles
Q. Zhang,P. A. Rubini +1 more
TL;DR: In this paper, a simplified model for the prediction of light extinction through combustion generated smoke is presented, which builds upon existing theory and available experimental data to account for the principal factors that influence light extinction in participating media, including wavelength, primary particle size distribution and morphological structure of particle aggregation.
Journal ArticleDOI
The Influence of Currents on the Ignition and Correlative Smoke Productions for PVC-Insulated Electrical Wires
TL;DR: In this article, a simplified theoretical analysis was developed to quantitatively explain the effects of currents on the ignition of electrical wires, and experiments with several sample wires were conducted to study the ignition process.
References
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Journal ArticleDOI
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Journal ArticleDOI
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Journal ArticleDOI
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Journal ArticleDOI
Comparison of a fractal smoke optics model with light extinction measurements
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