Flame base structure of small-scale pool fires

Venkatesh, Sriram; Ito, Akihiko; Saito, Kozo; Wichman, Indrek S.

doi:10.1016/s0082-0784(96)80364-x

Cited by 43 publications

(11 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compartment slit distance was changed from 0 (no fire whirl) to 4 cm to experimentally obtain the most stable fire whirl generation condition, the slit distance of 2 cm. 1-propanol was chosen because it emits less soot, a favorable condition for PIV measurement in comparison to sooty hydrocarbon fuels, and also because it can represent structures of light-soot hydrocarbon and alcohol pool fires [13].…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Note that our PIV measurements at the radial distance larger than 3.5 cm are expected to be accurate, while for 0 < r < 3.5 cm they are not accurate due to evaporation of the seeding particles. This shows some differences in the velocity structure between open pool fires and fire whirls, because the location of the maximum flow velocity and visible flame approximately coincides for laminar open pool fires [13,16,17,18]. The PIV radial velocity distribution by Gore et al [18] for a 7.1 cm diameter methane/air open pool fire (without swirl) at z = 5 cm is also added in the figure.…”

Section: Ir Temperature Measurementmentioning

confidence: 95%

See 1 more Smart Citation

Flow Structure Of A Fixed-frame Type Firewhirl

Hassan¹,

Kuwana²,

Saito³

et al. 2005

Fire Safety Science - Proceedings of the Eigth International Sy

Self Cite

View full text Add to dashboard Cite

This paper reports the results of both experimental and numerical investigations on a laboratory-scale fixed-frame type fire whirl. We designed a fixed-frame type fire whirl generator consisting of two vertically oriented split PMMA cylinders which are placed in an off-center location to create a small compartment with a slit at each end. At the center of the compartment floor, a 5 cm-diameter 1-propanol pool fire generated upward buoyancy flow and fresh air entering the compartment through the slits, generating swirl motion in the compartment. This is a fixed-frame type fire whirl. We measured transient 2-D radial, tangential, and axial velocity profiles with 2-D particle image velocimetry (PIV). The radial and tangential velocity profiles were measured at four different heights (5, 10, 15, and 20 cm) along the axis of the fire whirl, while the axial velocity profiles were measured at 10 cm in the axial height. We also measured relative temperature distributions of the fire whirl with an infrared thermograph technique. These measurements show that both the tangential velocity and the absolute value of radial velocity increase with an increase in the radial distance, while they remain relatively constant along the axis. Our IR data also show that the relative temperature map stays unchanged along the axis. The radial locations where the maximum radial and tangential velocity were measured approximately coincide and are at about 3.5 cm on the radial coordinate, while the visible spinning flame location is at about 1.2 cm. This shows a difference in the velocity structure between open pool fires and fire whirls, because the location of the maximum flow velocity and visible flame approximately coincides for laminar open pool fires. A simple laminar 2-D axisymmetric CFD model was developed to simulate these measured flow and temperature structures created by the fire whirl, and reasonable agreement was obtained.

show abstract

Section: Experimental Methodsmentioning

confidence: 99%

Section: Ir Temperature Measurementmentioning

confidence: 95%

Flow Structure Of A Fixed-frame Type Firewhirl

Hassan¹,

Kuwana²,

Saito³

et al. 2005

Fire Safety Science - Proceedings of the Eigth International Sy

Self Cite

View full text Add to dashboard Cite

show abstract

“…A primary anchoring zone (PAZ) above a pool fire was observed by Venkatesh et al [23]. Using video camera of 30 frames per second, flame shapes of an IFW of 5-cm diameter pool fire was also observed by Chuah and Kushida [24] to have some air regions above the burning fuel surface.…”

Section: Observation Using High-speed Cameramentioning

confidence: 81%

Observation on a fire whirl in a vertical shaft using high-speed camera and associated correlation derived

et al. 2021

View full text Add to dashboard Cite

The fire whirl generated by burning a pool fire in a vertical shaft with a single corner gap of appropriate width was studied using a high-speed camera. A 7-cm diameter pool propanol fire with heat release rate 1.6 kW in free space was burnt inside a 145-cm tall vertical shaft model with gap widths lying between 2 cm and 16 cm. The flame height was between 0.25 m and 0.85 m for different gap widths. Photographs taken using a high-speed camera at critical times of swirling motion development were used to compare with those taken using a normal camera. From the experimental observations on flame swirling by a high-speed camera, stages for generating the fire whirl were identified much more accurately. Two flame vortex tubes moving over the horizontal burning surface of the liquid pool were observed. Based on these observations a set of more detailed schematic diagrams on the swirling motion was constructed. From the observed flame heights under different gap widths and using three assumptions on the variation of air entrainment velocity with height, an empirical expression relating the burning rate with flame height and the corner gap width was derived from the observation with high-speed camera. The correlation expression of the burning rate of the pool fire obtained would be useful in fire safety design in vertical shafts of tall buildings.

show abstract

“…The second work examines the gas flow and flame attachment regions of a pool of burning fuel. 9 Once again, a strict comparison is not possible. However, it is experimentally shown 9 that the flame-tip structure is not that of a free, isenthalpic triple flame seen in Ref.…”

Section: Comparison With Experimentsmentioning

confidence: 99%

“…It can also represent flame spread 4 through the use of the conformal mapping ϭsin(z/2), zϭxϩiy, which folds down the side walls while producing a DF that lies close to a radial arc; see The literature of DF attachment is large. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Nonintrusive experimental diagnostics have been applied to this problem. In the development of models, recent emphasis has been placed on mixing and the chemical reaction.…”

Section: Introductionmentioning

confidence: 99%

Theory of attached and lifted diffusion flames

Wichman

Ramadan

1998

Physics of Fluids

View full text Add to dashboard Cite

Diffusion flame ͑DF͒ attachment and liftoff are examined, leading to ͑1͒ explanations of the origins of previous, successful empirical correlations; ͑2͒ the discovery of multiple lifting regimes. The latter includes a very slow flow regime, a slow-to-moderate flow regime, and a moderate-to-fast flow regime. Formulas for liftoff height ( l g ) and characteristic flame tip breadth ( l r ) are developed from a combination of the differential and integral form of the conservation equations. These formulas are compared with numerical solutions of the same equations.

show abstract

Flame base structure of small-scale pool fires

Cited by 43 publications

References 10 publications

Flow Structure Of A Fixed-frame Type Firewhirl

Flow Structure Of A Fixed-frame Type Firewhirl

Observation on a fire whirl in a vertical shaft using high-speed camera and associated correlation derived

Theory of attached and lifted diffusion flames

Contact Info

Product

Resources

About