Experimental observations of spot radiative ignition and subsequent three-dimensional flame spread over thin cellulose fuels

Olson, Sandra L.; Kashiwagi, T.; Fujita, Osamu; Kikuchi, Masao; Ito, Kenichi

doi:10.1016/s0010-2180(00)00249-2

Cited by 57 publications

(27 citation statements)

References 9 publications

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“…The premixed flame propagated through the cloud and ignited the heated second rod. The critical heat flux for ignition in the absence of convective cooling is just slightly more than offsets the experimental heat losses such as surface radiation at T ign [4], which agrees with the model of Rhodes and Quintiere [9] in the limit of no convection, and is consistent with observations that ignition is easier in microgravity [15].…”

Section: Ignition Delaysupporting

confidence: 88%

Convective Heat Transfer Scaling of Ignition Delay and Burning Rate with Heat Flux and Stretch Rate in the Equivalent Low Stretch Apparatus

Olsen¹

2011

Fire Safety Science - Proceedings of the 10th International Sym

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To better evaluate the buoyant contributions to the convective cooling (or heating) inherent in normal gravity material flammability test methods, we derive a convective heat transfer correlation that can be used to account for the forced convective stretch effects on the net radiant heat flux for both ignition delay time and burning rate. The equivalent low stretch apparatus (ELSA) uses an inverted cone heater to minimize buoyant effects while at the same time providing a forced stagnation flow on the sample, which ignites and burns as a ceiling fire. Ignition delay and burning rate data is correlated with incident heat flux and convective heat transfer and compared to results from other test methods and fuel geometries using similarity to determine the equivalent stretch rates and thus convective cooling (or heating) rates for those geometries. With this correlation methodology, buoyant effects inherent in normal gravity material flammability test methods can be estimated, to better apply the test results to low stretch environments relevant to spacecraft material selection.

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Section: Ignition Delaysupporting

confidence: 88%

Convective Heat Transfer Scaling of Ignition Delay and Burning Rate with Heat Flux and Stretch Rate in the Equivalent Low Stretch Apparatus

Olsen¹

2011

Fire Safety Science - Proceedings of the 10th International Sym

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“…Significant effort has already been applied to understanding ignition delay in microgravity conditions, both theoretically and experimentally [5][6][7][8][9]. The conclusion drawn from each of the above studies is that in the low velocity flows commonly encountered in space-based facilities, piloted ignition delay times are shorter than those in the buoyancy-induced flows of normal gravity.…”

Section: Introductionmentioning

confidence: 99%

Piloted ignition delay of PMMA in space exploration atmospheres

McAllister

Fernandez-Pello

Urban

et al. 2009

Proceedings of the Combustion Institute

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“…Two cases were compared: an open configuration and a specific test chamber (8.5 cm wide, 9.5 cm high, and 17.1 cm long). used in their microgravity experiments (Olson et al 2001). The results showed that the flame spread rate for the enclosure case is faster than that for the open case, and the effects of the enclosure are most significant in the oxygen-controlled regime.…”

Section: Introductionmentioning

confidence: 99%

“…A number of experimental studies have investigated flame spread over thermally thin solids in actual (e.g., Andracchio and Cochran 1976;Olson et al 1988Olson et al , 1991Olson et al , 2001Grayson et al 1994;Ramachandra et al 1995;Kashiwagi et al 1996;Sacksteder et al 1998) or simulated (Olson et al 2009;Zhang and Yu 2011) microgravity conditions during the past decades. The primary variables considered so far included flow velocity, oxygen concentration, fuel thickness and width, and flow direction (opposing that of flame propagation, or in the same direction as that of propagation).…”

Section: Introductionmentioning

confidence: 99%

Opposed-flow Flame Spread Over Solid Fuels in Microgravity: the Effect of Confined Spaces

Wang

Xiao

et al. 2015

Microgravity Sci. Technol.

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Effects of confined spaces on flame spread over thin solid fuels in a low-speed opposing flow is investigated by combined use of microgravity experiments and computations. The flame behaviors are observed to depend strongly on the height of the flow tunnel. In particular, a non-monotonic trend of flame spread rate versus tunnel height is found, with the fastest flame occurring in the 3 cm high tunnel. The flame length and the total heat release rate from the flame also change with tunnel height, and a faster flame has a larger length and a higher heat release rate. The computation analyses indicate that a confined space modifies the flow around the spreading flame. The confinement restricts the thermal expansion and accelerates the flow in the streamwise direction. Above the flame, the flow deflects back from the tunnel wall. This inward flow pushes the flame towards the fuel surface, and increases oxygen transport into the flame. Such a flow modification explains the variations of flame spread rate and flame length with tunnel height. The present results suggest that the confinement effects on flame behavior in microgravity should be accounted to assess accurately the spacecraft fire hazard.

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Experimental observations of spot radiative ignition and subsequent three-dimensional flame spread over thin cellulose fuels

Cited by 57 publications

References 9 publications

Convective Heat Transfer Scaling of Ignition Delay and Burning Rate with Heat Flux and Stretch Rate in the Equivalent Low Stretch Apparatus

Convective Heat Transfer Scaling of Ignition Delay and Burning Rate with Heat Flux and Stretch Rate in the Equivalent Low Stretch Apparatus

Piloted ignition delay of PMMA in space exploration atmospheres

Opposed-flow Flame Spread Over Solid Fuels in Microgravity: the Effect of Confined Spaces

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