Piloted ignition delay of PMMA in space exploration atmospheres

McAllister, Sara; Fernandez-Pello, Carlos; Urban, David L.; Ruff, Gary A.

doi:10.1016/j.proci.2008.05.076

Cited by 36 publications

(16 citation statements)

References 17 publications

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“…At present, most low‐pressure fire studies compare the combustion characteristics of the same fuel at different altitudes . The experiments were primarily done in Lhasa (altitude, 3650 m; pressure, P = 64.3 kPa) and Hefei (altitude, 50 m; P = 101 kPa), and a small number of fire tests were performed at three to four altitudes and in a low‐pressure chamber . The fire test fuel was classified into gaseous, liquid, and solid fuel, and similar conclusions have been reached: In higher‐altitude areas, the flame height, flame volume, ignition temperature, and ignition time increase, but the burning rate and flame pulsation decrease.…”

Section: Introductionmentioning

confidence: 85%

“…1,2 The experiments were primarily done in Lhasa (altitude, 3650 m; pressure, P = 64.3 kPa) and Hefei (altitude, 50 m; P = 101 kPa), and a small number of fire tests were performed at three to four altitudes 3,4 and in a low-pressure chamber. [5][6][7][8][9] The fire test fuel was classified into gaseous, 10,11 liquid, 2,[12][13][14] and solid fuel, [15][16][17][18] and similar conclusions have been reached: In higher-altitude areas, the flame height, flame volume, ignition temperature, and ignition time increase, but the burning rate and flame pulsation decrease. The mass burning rate, radiative heat flux, heat release rate, and combustion efficiency in Lhasa were lower than those in Hefei, and the relationship between the burning rate and the ambient pressure could be simulated with the power function.…”

Section: Introductionmentioning

confidence: 85%

“…First, the high‐altitude area test was limited by seasons, and the suitable test time was scarce. Second, it was difficult to conduct large‐scale fire research because of the limited pressure and size of the chamber, which usually prohibited the enrichment of oxygen and air . Finally, large‐scale fire tests were costly and difficult to accurately measure .…”

Section: Introductionmentioning

confidence: 99%

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A new approach based on the modified FDS to numerically simulate cardboard box combustion under low pressure

Zhou

Zhao

et al. 2019

Fire and Materials

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Summary To solve the limitation of the fire test in high‐altitude areas only detecting a limited number of low‐pressure environments, in this paper, appropriate modifications of the FDS source codes were made to generate a new simulator program for low‐pressure applications. Standard fire experiments with different counts (1, 2, 18, and 27) of cardboard boxes were numerically simulated under different pressure levels (101, 90, 75, and 64 kPa). The computation data show consistent trends with the experimental results obtained in the low‐pressure tank at Lang Fang. Furthermore, the simulation results have been examined to show typical quantitative relationships: (a) The peak mass burning rate divided by the fire base dimension is correlated with the product of the pressure squared and the combustible characteristic length cubed. The exponential indices for the 1‐box fire, 18‐box fire, and 27‐box fire are 0.31, 0.29, and 0.29, respectively. (b) The heat release rate and mass burning rate show a good linearity at each fixed environmental pressure. In conclusion, the modified FDS is validated to work well under low‐pressure conditions, which can provide a receivable means to conduct low‐pressure fire simulation and analysis.

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Section: Introductionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

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A new approach based on the modified FDS to numerically simulate cardboard box combustion under low pressure

Zhou

Zhao

et al. 2019

Fire and Materials

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“…In series 2, since the Reynolds number is constant, the convective heat transfer coefficient can be regarded as constant (McAllister, et al, 2009), (Gabour and Lienhard, 1994). The factors which may cause a change in the fuel gasification rate are either the temperature in the vicinity of the fuel surface, or a change in the gasification enthalpy of the solid fuel (Han, et al, 2005), (Kissinger, 1954) .…”

Section: Additional Discussionmentioning

confidence: 99%

“…This would also have an effect on activation energy E and B number, which could explain the deviation of blowoff limit between series 1 and series 2 (Kayacan and Dogan, 2008). In McAllister's studies (McAllister, et al, 2009), the ignition time of a PMMA fuel sample was shortened when the pressure was decreased.…”

Section: Additional Discussionmentioning

confidence: 99%

Effect of combustion pressure on regression rate of solid fuel under an impinging oxidizer jet counterflow diffusion flame

Terakawa

Saito

Nakamura

et al. 2014

JTST

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Flame spread and counterflow diffusion flame experiments are widely conducted to investigate the combustibility of solid fuels. Although the use of the gas phase Damköhler number to organize the flame spread rate or regression rate of a solid fuel is effective under constant pressure, some research point out the possibility that the combustion pressure may be an independent factor in determining the regression rate. This research employs a counterflow diffusion flame to investigate the effects of combustion pressure on regression rate, and clarifies the deviation of results using the classical Damköhler number under varying pressures. First, a numerical flow analysis was conducted to determine the oxidizer velocity gradient near the fuel surface, which is an essential factor in evaluating the non-dimensional regression rate. Next, using an enclosed combustion chamber with independently variable oxidizer flux and pressure, experiments with a quasi two-dimensional flame were conducted with polyethylene solid fuel and nitrogen diluted oxygen oxidizer, and the regression rate was measured for two experiment series, constant pressure, and constant oxidizer flux. By comparing the two series, the effect of pressure on non-dimensionalized regression rate is clarified. The results suggest that contrary to the theoretical reaction rate of the gas phase, the non-dimensional regression rate increases when the combustion pressure is decreased, even in the thermal regime. This suggests that the classic method of organizing the regression rate with Damköhler number in thermal regime could not be implemented with varying pressure conditions, possibly due to the change in diffusion rates involved with varying pressures.

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Fire behaviors of vertical and horizontal polymethyl methacrylate slabs under autoignition conditions

Huang

Wang

Shen

et al. 2019

Process Safety Progress

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In this study, horizontal and vertical black polymethyl methacrylate (PMMA) samples were investigated experimentally and theoretically under 25‐70 kW/m2 heat flux with autoignition conditions. An empirical model was developed to predict the autoignition time, where the significance of this model is to unify the prediction for both horizontal and vertical samples. Both horizontal and vertical samples show similar phenomena, such as burning stages and no higher than 2 cm sample expansion. It is obtained that the vertical samples show averagely 21% lower CO yield and also longer ignition time than those of the horizontal samples, while the CO2 yield increases about 24%. However, the vertical samples show a relatively high fire risk. This can be reflected by higher surface temperature, bigger average heat release rate (HRR) and mass loss rate (MLR), higher peak MLR, longer bubbling stage, higher CO2 yield, where the differences become even bigger under a higher external heat flux. A linear relationship was found between the average HRR of vertical and horizontal samples, and also between the ignition temperature and external heat flux for both orientated samples. The research outcomes provide a practical basis and guide for the risk assessment of combustible materials under both vertical and horizontal orientation.

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Piloted ignition delay of PMMA in space exploration atmospheres

Cited by 36 publications

References 17 publications

A new approach based on the modified FDS to numerically simulate cardboard box combustion under low pressure

A new approach based on the modified FDS to numerically simulate cardboard box combustion under low pressure

Effect of combustion pressure on regression rate of solid fuel under an impinging oxidizer jet counterflow diffusion flame

Fire behaviors of vertical and horizontal polymethyl methacrylate slabs under autoignition conditions

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