The Effect of Gravity on Flame Spread over PMMA Cylinders in Opposed Flow with Variable Oxygen Concentration.

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dc.creatorLink, Shmuel
dc.creatorHuang, Xinyan
dc.creatorOlson, Sandra
dc.creatorFerkul, Paul
dc.creatorFernandez-Pello, Carlos
dc.date.accessioned2016-07-28T18:07:13Z
dc.date.available2016-07-28T18:07:13Z
dc.date.issued2016-07-10
dc.descriptionUnited States
dc.descriptionUniversity of California Berkeley
dc.descriptionNASA
dc.descriptionuniversity of california berkeley
dc.description509
dc.descriptionICES509: Fire Safety in Spacecraft and Enclosed Habitats
dc.descriptionVienna, Austria
dc.descriptionShmuel Link, University of California Berkeley Department of Mechanical Engineering, USA
dc.descriptionXinyan Huang, University of California Berkeley Department of Mechanical Engineering, USA
dc.descriptionCarlos Fernandez-Pello, University of California Berkeley Department of Mechanical Engineering, USA
dc.descriptionSandra Olson, NASA Glenn Research Center at Lewis Field, USA
dc.descriptionPaul Ferkul, NASA Glenn Research Center at Lewis Field, USA
dc.descriptionThe 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.
dc.description.abstractFire safety is an important concern for space travel, particularly with the operation of proposed space missions such as those of NASA’s Constellation Program. Currently there is not sufficient knowledge regarding the fire behavior of materials in environments similar to those expected in those future spacecraft (micro-gravity, low velocity flow, elevated oxygen, and reduced pressures. Flammability of solid materials is typically characterized by ignitability, flame spread rate, heat release rate, and toxicity. Although, the most effective fire safety strategy is to prevent ignition altogether, if ignition occurs the fire has to spread to present a risk. The spread of flames over cylindrical samples of cast PMMA of different diameters was investigated to better understand the effects of gravity and oxygen on the mechanisms of flame spread. The 1g experiment consisted of determining the opposed flow spread rate for 3 sample diameters (6.3, 9.5, and 12.7 mm) in gas flows with oxygen concentrations from 21% to 15% and a velocity of 25 cm/s. The micro-gravity flame-spread experiments were conducted as a part of the Burning and Suppression of Solids - II (BASS-II) campaign of micro-gravity combustion experiments conducted aboard the ISS. Opposed flame spread rates were measured for the above samples under flow velocities from 0.5 to 5 cm/s. and oxygen concentrations from 21% to 15%. It was found that for all comparable oxygen concentrations and diameters flame spread in μg was faster than in 1g conditions. A numerical modeling of flame-spread over cast PMMA rods as a function of ambient oxygen concentration and gravity was conducted using FDS. The modeling predicts the observed experimental trends qualitatively but not quantitatively. This is most likely due to the approximate description of the solid phase pyrolysis and gas phase chemistry. The work was supported by NASA Grants NNX10AE01G
dc.identifier.otherICES_2016_79
dc.identifier.urihttp://hdl.handle.net/2346/67515
dc.language.isoeng
dc.publisher46th International Conference on Environmental Systems
dc.subjectflame spread
dc.subjectmicro-gravity
dc.subjectoxygen concentration
dc.titleThe Effect of Gravity on Flame Spread over PMMA Cylinders in Opposed Flow with Variable Oxygen Concentration.
dc.typePresentation

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