Publicou 12 edições por ano
ISSN Imprimir: 1044-5110
ISSN On-line: 1936-2684
Indexed in
TRANSPORT OF HIGH BOILING POINT FIRE SUPPRESSANTS IN A DROPLET-LADEN HOMOGENEOUS TURBULENT FLOW PAST A CYLINDER
RESUMO
Liquid agent transport was investigated around unheated and heated horizontal cylinders (to a near-surface temperature of approximately 423 K, i.e., well above the water boiling point) under ambient conditions. Experimental results are presented for a well-characterized, droplet-laden homogenous turbulent flow field, using water, methoxy-nonafluorobutane (i.e., HFE-7100, C4F9OCH3, with a boiling point of 334 K), and 1-methoxyheptafluoropropane (i.e., HFE-7000, C3F7OCH3, with a boiling point of 307 K). Phase Doppler interferometry and visualization techniques were used to explore the thermal effects on spray surface impingement, vaporization, and transport around and downstream behind the cylinder by providing information on droplet size and velocity in the vicinity of the cylinder. For water, results indicated that impinging droplets larger than about 35 μm generally coat the unheated cylinder surface, with few droplets rebounding back into the free stream. Downstream, in the wake region of the cylinder, smaller size droplets (generally, of less than 35 μm) are entrained into the recirculation zone. Heat transfer reduces droplet mean size and velocity significantly in the vicinity of the heated cylinder. For the two HFE agents, liquid coating and dripping (observed for water) were eliminated due to vaporization. Droplet mean size increases and velocity decreases with increasing agent boiling point. These variations may also be explained by the changes in agent physical properties. It is improbable that shattering occurs for the droplet sizes and velocities encountered for the given operating conditions, although it could conceivably occur for a few individual impinging droplets.
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Presser Cary, Papadopoulos George, Widmann John F., PIV measurements of water mist transport in a homogeneous turbulent flow past an obstacle, Fire Safety Journal, 41, 8, 2006. Crossref
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Presser C., Yang J. C., Fire Suppression, in Handbook of Atomization and Sprays, 2011. Crossref
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Li Xiutao, Zhou Zhenyang, Zhang Mengjie, Zhang Feng, Zhou Xiaomeng, A liquid cooling technology based on fluorocarbons for lithium-ion battery thermal safety, Journal of Loss Prevention in the Process Industries, 78, 2022. Crossref
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An Sang Mo, Lee Sang Yong, Observation of the spreading and receding behavior of a shear-thinning liquid drop impacting on dry solid surfaces, Experimental Thermal and Fluid Science, 37, 2012. Crossref