Study on Prefire Phenomena of Wire Insulation at Microgravity

Kong, Wenjun; Wang, Baorui; Zhang, Weikuo; Ai, Yuhua; Lao, Shiqi

doi:10.1007/s12217-008-9041-4

Cited by 20 publications

(11 citation statements)

References 7 publications

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“…Both the experimental system and the wire in the FS experiment are the same as those used in the microgravity experiment on board the SJ-8 China recoverable satellite. 18 Based on equation 1, the pressure in the steel cabin in the experiments on the ground is reduced to simulate the effect of gravity on the pre-ignition temperatures of the wire insulation in quiescent microgravity environment. In addition, the effects of ambient pressure and overload current on the pre-ignition temperature variations of wire insulation were investigated.…”

Section: Experimental Facility and Processmentioning

confidence: 99%

“…[8][9][10][11][12][13][14][15][16] However, ignition of wire insulation by external sources in general does not represent typical fire scenarios on board of a space shuttle. In 2006, Kong et al 17,18 conducted the first long-duration microgravity experiment on board of SJ-8 China satellite. They obtained the valuable pre-ignition temperature variations of wire insulation under overload current, showing that they are quite different from those in the normal gravity.…”

Section: Introductionmentioning

confidence: 99%

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Study on the pre-ignition temperature variations of wire insulation under overload conditions in microgravity by the functional simulation method

Wang

Kong

et al. 2013

Journal of Fire Sciences

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A functional simulation method was applied to study the pre-ignition temperature variations of wire insulation under overload conditions in normal gravity. A simplified heating mode was proposed to theoretically investigate the wire heating process. Results of the temperature variations of wire insulation prior to ignition in normal gravity, but under reduced pressures, were obtained and compared with microgravity experimental results in order to investigate the effects of pressure and current on the pre-ignition thermal features of the wire insulation. Results show that the functional simulation method was effective to simulate the natural convection heat transfer effect on the wire insulation, which is a useful alternative approach to predict the pre-ignition thermal features of wire insulation by overload over a long duration in a microgravity environment.

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Section: Experimental Facility and Processmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Study on the pre-ignition temperature variations of wire insulation under overload conditions in microgravity by the functional simulation method

Wang

Kong

et al. 2013

Journal of Fire Sciences

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“…Groundbased facilities and numerical simulations served as the main source of previous work in microgravity combustion studies in China. Two unique space experiments [62,63] designed and prepared by the combustion researchers at the Institute of Mechanics and the Institute of Engineering Thermophysics, CAS respectively, were carried out on board China's recoverable satellite SJ-8 in September 2006. These experiments were concerned with the smoldering characteristics of polyurethane foam and prefire characteristics of wire insulation, respectively.…”

Section: Microgravity Combustion Experimentsmentioning

confidence: 99%

“…Particularly no information can be obtained from these experiments about the precursors of fire incidents. The microgravity experiments on board the SJ-8 satellite were developed to study fire precursors of wire insulations caused by overload [63] . The fire initiation characteristics of wire insulations, including the temperature and radiation characteristics, were measured in a quiescent atmosphere.…”

Section: Microgravity Combustion Experimentsmentioning

confidence: 99%

Space experimental studies of microgravity fluid science in China

Long

Kang

et al. 2009

Chin. Sci. Bull.

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Microgravity fluid physics is an important part of microgravity sciences, which consists of simple fluids of many new systems, gas-liquid two-phase flow and heat transfer, and complex fluid mechanics. In addition to the importance of itself in sciences and applications, microgravity fluid physics closely relates to microgravity combustion, space biotechnology and space materials science, and promotes the developments of interdisciplinary fields. Many space microgravity experiments have been performed on board the recoverable satellites and space ships of China and pushed the rapid development of microgravity sciences in China. In the present paper, space experimental studies and the main results of the microgravity fluid science in China in the last 10 years or so are introduced briefly. microgravity fluid physics, microgravity gas-liquid two-phase flow, microgravity complex fluid, microgravity combustion, space biotechnologyThe technologies of rockets and satellites require the study of the fluid management problem in the storage tanks, and such problems of microgravity engineering in the microgravity environment have been studied in China during the development of space technology [1] . Studies on microgravity sciences in China were started in the late 1980s, when the scientists completed some space experiments on board the Chinese recoverable satellites by the promotion of the National HighTechnology Research Program of China. Main research subjects were the scientific experiments of materials science, in charged by the experts of the Institute of Semiconductor of the Chinese Academy of Sciences (CAS) and the Lanzhou Institute of Physics [2][3][4] , and experiments of space biology, in charged by the experts of life sciences in the CAS [5][6][7] . Some nice results were obtained, although resources of space experiments on board the recoverable satellite were relatively limited in the preliminary period.Microgravity fluid physics is an import part of microgravity sciences, and requires relatively complicated experimental facility in general, mostly the optical diagnostic instrumentations. Theoretical and experimental studies of the microgravity fluid physics on the ground were started relatively early in China [8] ; the scientists of China and Japan jointly completed the microgravity experiments of the thermocapillary convection in floating half zone [9] and drop Marangoni migration [10] using the JAMIC drop shift in Hokkaido and the MGLAB drop shift in Toki respectively before the foundation of the Beijing Drop Tower, and the experimental results were nice. China's first space experiment of fluid physics was completed 10 years later after the initiation of one of the materials science. The experiments of Marangoni convection and thermocapillary convection in two immiscible liquid layers were performed on board the SJ-5

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“…A large number of studies have been undertaken previously on addressing the fire behaviors of wires [ 4 ]. The influencing factors of the relevant fire spreading considered in these studies including inclination angles [ 5 ], AC electrical fields [ 6 ], oxygen concentration [ 7 ], external radiation intensity [ 8 ], ambient pressure [ 9 , 10 , 11 ], and gravity [ 12 , 13 , 14 , 15 ]. Besides these influencing factors, their ignition behaviors were investigated under various scenarios, such as short-term overcurrent [ 16 , 17 ], external heat flux [ 18 ], arc formation [ 19 , 20 ], subatmospheric [ 21 , 22 ], and microgravity [ 23 , 24 ].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Thermoplastic Dripping and Flame Spread Behaviors of Energized Electrical Wire under Reduced Atmospheric Pressure

Zhang

Shi

et al. 2021

Polymers

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Flame spread over wire surface is different from other solid fires as it is usually accompanied by melting and dripping processes. Although the related behaviors at reduced pressure (20–100 kPa) are significant to those fire risk evaluations, very few studies have been undertaken on this matter. Therefore, the thermoplastic dripping and flame spread behaviors of energized polyethylene insulated copper wires were investigated experimentally at reduced pressure. It was known from experimental results that the dripping frequency increases, showing a relatively smooth (linear) and rapid (power) increasing trends under high and low electrical currents, respectively. A short-period flame disappearance was observed during the dripping process, which is unique for the energized wire at reduced pressure. The bright flame can disappear for several seconds and then show again after the dripping. While at 20 kPa or lower, the wire flame would turn to a completed extinguishment after the dripping. A critical dripping point was proposed to show the minimal required electrical current to sustain the flame spearing. The critical current changes smoothly during 100–80 kPa and decreases rapidly at 80–60 kPa. Additionally, the dripping phenomenon can stop or delay the flame spread, partly because of the short-term flame disappearance.

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Study on Prefire Phenomena of Wire Insulation at Microgravity

Cited by 20 publications

References 7 publications

Study on the pre-ignition temperature variations of wire insulation under overload conditions in microgravity by the functional simulation method

Study on the pre-ignition temperature variations of wire insulation under overload conditions in microgravity by the functional simulation method

Space experimental studies of microgravity fluid science in China

Experimental Study on the Thermoplastic Dripping and Flame Spread Behaviors of Energized Electrical Wire under Reduced Atmospheric Pressure

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