Scaling fire whirls

Kuwana, Kazunori; Sekimoto, Kozo; Saito, Kozo; Williams, Forman A.

doi:10.1016/j.firesaf.2007.10.006

Cited by 107 publications

(70 citation statements)

References 23 publications

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“…1 denotes the Froude number Fr based on the axial velocity component and can be used to indicate the role of buoyancy in the flame structure or formation (Emori & Saito 1982;Grishin et al 2005;Akhmetov et al 2007;Kuwana et al 2007Kuwana et al , 2008. 2 is the (vortex core) Reynolds number Re based on the azimuthal velocity component (Mullen & Maxworthy 1977), and 7 is the flow's Prandtl number Pr.…”

Section: Introductionmentioning

confidence: 99%

Fire Whirls

Tohidi

Gollner

Xiao

2018

Annu. Rev. Fluid Mech.

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Fire whirls present a powerful intensification of combustion, long studied in the fire research community because of the dangers they present during large urban and wildland fires. However, their destructive power has hidden many features of their formation, growth, and propagation. Therefore, most of what is known about fire whirls comes from scale modeling experiments in the laboratory. Both the methods of formation, which are dominated by wind and geometry, and the inner structure of the whirl, including velocity and temperature fields, have been studied at this scale. Quasi-steady fire whirls directly over a fuel source form the bulk of current experimental knowledge, although many other cases exist in nature. The structure of fire whirls has yet to be reliably measured at large scales; however, scaling laws have been relatively successful in modeling the conditions for formation from small to large scales. This review surveys the state of knowledge concerning the fluid dynamics of fire whirls, including the conditions for their formation, their structure, and the mechanisms that control their unique state. We highlight recent discoveries and survey potential avenues for future research, including using the properties of fire whirls for efficient remediation and energy generation.

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Section: Introductionmentioning

confidence: 99%

Fire Whirls

Tohidi

Gollner

Xiao

2018

Annu. Rev. Fluid Mech.

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“…The vortex can be characterized by two parameters, i.e. the radius R of the vortex core in solid-body rotation and the circulation Г, which appeared in Kuwana's analysis for the flame height of fire whirl [3]. In our test, the circulation =2 rV    is nearly constant independent of r out of flame.…”

Section: Vertical Centerline Velocity Of Fire Whirlmentioning

confidence: 78%

“…Fire whirls, generally caused by an unexpected vortex flow effect on the flame burning, are often reported in forest and urban fires with devastating damage to life and property, and also contribute to spot fires by picking up large firebrands and scattering them over a wide area [1][2][3]. During the past half century, a number of theoretical and experimental studies have been conducted to provide a basic understanding of the fire whirl phenomenon.…”

Section: Introductionmentioning

confidence: 99%

“…Morton [5] especially examined the origin, generation and amplification of concentrated vorticity of fire whirl by analysis of relevant vorticity equations. The burning behaviors including burning rate, flame height and flame temperature were mainly investigated by experimental researchers, such as Emmons and Ying [7] by rotating screen-flame model, Soma and Saito [2] and Kuwana et al [3] utilizing bench-scale model by scaling laws, and Lei et al [8] by fixed frame-flame model. In recent years, numerical simulations [9,10] have also been widely used for solving the Navier-Stokes or vorticity equations of fire whirl, in order to interpret the detailed fluid flow structure.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental Research on Burning Rate, Vertical Velocity and Radiation of Medium-Scale Fire Whirls

Zhou¹,

Liu²,

Satoh³

2011

Fire Safety Science - Proceedings of the 10th International Sym

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Fire whirls are often reported in forest and urban fires with devastating damage to life and property. This work conducted experiments using a medium-scale facility to study the initiation mechanism, the vertical velocity and radiative heat transfer of fire whirls. Heptane was used as the fuel in the experiments. The variations of burning rates versus time indicate that the drag force on the root of the flame plays an important role in the initiation and decay of a fire whirl. Analyses show that the pressure difference due to whirling, characterized by the circulation  , significantly affects the vertical centerline velocity. The variation of the vertical centerline velocity is correlated by , where m is nearly 1.1 for both fire whirls and general pool fires. It is also found that the radiative fraction of fire whirls is nearly 42 %, 1.4 times as large as that for general pool fires. The radiative heat feedback fraction is shown to increase with pool diameter, similarly as for general pool fires. KEYWORDS: fire whirl, radiation, centerline velocity, burning rate, pool fires. NOMENCLATURE LISTING

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“…Aiming at a property and elucidation of an outbreak factor of fire whirlwind as examples of the pasts for a lesson, investigation and a reproduction experiment of the outbreak situation (Graham, 1955;Emmons & Ying, 1967;Byram & Martin, 1970;Haines & Updike, 1971;Martin et al, 1976;Muraszew et al, 1979;Emori & Saito, 1982;Satoh & Yang, 1996;Hayashi et al, 2003;Liu, 2005;Kuwana et al, 2007;Liu et al, 2007;Kuwana et al, 2008;Chuah et al, 2011), numerical analysis are performed till now (Satoh & Yang, 1997;Battaglia et al, 2000a;Battaglia et al, 2000b;Snegirev et al, 2004;Hassan et al, 2005;Chuah et al, 2007;Grishin, 2007;Grishin et al, 2009). Though various factors are thought about outbreak of a fire whirlwind, such as climatic condition or existence of underground flammable gas, it is hard www.intechopen.com…”

Section: Introductionmentioning

confidence: 99%

Numerical Prediction of Fire Whirlwind Outbreak and Scale Effect of Whirlwind Behavior

Sakai¹

2012

Advances in Geotechnical Earthquake Engineering - Soil Liquefaction and Seismic Safety of Dams and Monuments

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Scaling fire whirls

Cited by 107 publications

References 23 publications

Fire Whirls

Fire Whirls

Experimental Research on Burning Rate, Vertical Velocity and Radiation of Medium-Scale Fire Whirls

Numerical Prediction of Fire Whirlwind Outbreak and Scale Effect of Whirlwind Behavior

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