Flame Spread over Fuel-Spilled and/or Snow-Covered Asphalt Road

1996 ◽  
Vol 14 (1) ◽  
pp. 50-66 ◽  
Author(s):  
Hiroki Ishida ◽  
Katsuhisa Sato ◽  
Kozo Hokari ◽  
Tomio Hara
Keyword(s):  
Flame Spread ◽  
Liquid Fuel ◽  
Large Scale ◽  
Fire Hazard ◽  
Water Layer ◽  
Road Surface ◽  
Convection Flow ◽  
Snow Layer ◽  
Porous Asphalt ◽  
Asphalt Road

Flame spread characteristics over the fuel-spilled and/or snow- covered asphalt road (both porous and non-porous) were studied experimentally from the point of view of fire hazard prevention in many fuel spill accidents on the urban asphalt road. A large scale pool burning occurs on the non-porous usual asphalt road, but flame spread and pool burning cannot occur on the porous asphalt road owing to the drainage of fuel. When the liquid fuel was spilled on the snow-covered road and ignition occurred, the liquid fuel burns on the fuel-soaked sleety snow layer. On the thick snow layer, if the amount of spilled fuel was not so large, the combustion on the fuel-spilled region cannot continue for a long time, even for highly flammable fuels such as gasoline. However, if the snow layer was not so thick, and a large amount of fuel was spilled, the sleety snow layer beneath the flame reaches the road surface with the lapse of time of combustion. The water layer due to snow-melting is formed and pool burning occurs on the exposed road surface. On the porous asphalt road, however, such pool burning cannot occur because both the water and the fuel are drained. Comparison between the flame spread rate measured on the fuel-spilled snow-covered non-porous road and that predicted by a simplified model suggested that both the mechanism of combustion on fuel-soaked sleety snow layer and the scale effect, causing a strong fire-induced convection flow, should become important factors for flame spread on the snow-covered road.

scholarly journals Large scale experimental study on the fire hazard of buildings’ U-shape façade wall geometry

2017 ◽  
Vol 23 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Weigang YAN ◽  
Lin JIANG ◽  
Weiguang AN ◽  
Yang ZHOU ◽  
Jinhua SUN
Keyword(s):  
Theoretical Analysis ◽  
Flame Spread ◽  
Large Scale ◽  
Fire Hazard ◽  
Residential Building ◽  
Flame Height ◽  
Geometrical Factor ◽  
Insulation Material ◽  
Upward Flame Spread ◽  
Wall Geometry

Buildings have U-shape façade designs for certain purposes such as lighting. However, such designs may lead to a higher fire hazard. In this paper, large scale experiments of upward flame spread over XPS insulation material were conducted to investigate the fire hazard of building’s U-shape façade wall geometry. Comparison to previous labora­tory scale experiments were also presented. Theoretical analysis was performed to reveal the mechanism of the U-shape geometry’s influences. It is found that such geometry design would increase the fire hazard of buildings: flame spread rate and flame height increased with U-shape’s geometrical factor. The results agreed with theoretical analysis. It is ex­pected that the buildings’ U-shape façade wall geometry would greatly benefit flame spread for full scale applications and increase the fire hazard. Thus engineers should be careful with such façade wall designs, especially for residential building designs.

Polymers and Composites- An Examination of Fire Spread and Generation of Heat and Fire Products

1993 ◽  
Vol 11 (5) ◽  
pp. 421-441 ◽  
Author(s):  
Archibald Tewarson ◽  
Domenic P. Macaione
Keyword(s):  
Flame Spread ◽  
Large Scale ◽  
Fire Hazard ◽  
Chemical Properties ◽  
Weight Ratio ◽  
Thermal Response ◽  
Flame Extinction ◽  
Physico Chemical ◽  
Group 2 ◽  
Ignition Zone

Fiber reinforced composite (FRC) materials are used extensively because of their favorable physico-chemical properties and high strength- to-weight ratio. The use of composites in Army vehicles as a means of decreas ing weight and enhancing survivability, without reducing personnel safety, has been under study for some time. Although FRC materials are very attractive in terms of their physico-chemical properties, concern for possible fire hazard is understandable as organic polymers are one of the major constituents of the materials. A joint study thus was undertaken by the U.S. Army Materials Tech nology Laboratory (MTL) and the Factory Mutual Research Corporation (FMRC) to quantify flammability behavior of selected composite materials for the assessment of fire hazard. In the study, eight FRC materials, identified as MTL #1 to #8, were used. The FRC materials were 3 to 45 mm in thickness. The flammability behavior was examined by using the FMRC Flammability Apparatus (50 kW-Scale) and Ox ygen Index (OI) apparatus, Thermogravimetric Analysis (TGA) instrument, NBS smoke chamber (ASTM E 662), and Gas Chromatograph-Mass Spec trometer (GC-MS) instrument at MTL. This article presents results for ignition, flame spread, heat release rate, gen eration rates of products, light obscuration by smoke and flame extinction by Halon. In comparison to ordinary combustibles, such as cellulosics and most non fire retarded plastics, the eight FRC materials have higher resistance to ig nition (as indicated by the Thermal Response Parameter, TRP) and flame spread (as indicated by higher values of the Fire Propagation Index, FPI). The FPI values for the FRC materials, examined in this study, ranged from 3 to 13, indicating that for Group 1 FRC materials (FPI < 10), self-sustained flame spread beyond the ignition zone would be difficult, whereas for other Group 2 materials ( FPI ≥ 10), flame spread beyond the ignition zone would be ex pected, although at a slower rate. For Group 2 materials fire protection is re quired, which could be provided by techniques such as surface coating, surface lamination using highly fire resistant FRC materials, and others. Generation of heat, smoke, toxic and corrosive products is closely related to FPI. Within the FRC materials, examined in this study, differences were found between the generation rates of heat, smoke, and other products. Results for flame extinction by Halon 1301 are also discussed. The flame ex tinction data are consistent with the design of the current suppression system for the crew compartment of Army combat vehicles. The study suggests that the FPI concept and associated parameters related to generation of heat, smoke, toxic, and corrosive products, is a useful concept for realistic flammability quantification and screening of FRC materials and for use in the hazard assessment. This, however, needs to be validated by perform ing large-scale fire tests.

Increasing Running Shoe Traction can Enhance Performance

2014 ◽  
Vol 18 (2) ◽  
pp. 17-22 ◽  
Author(s):  
Jay T. Worobets ◽  
Fausto Panizzolo ◽  
Steve Hung ◽  
John W. Wannop ◽  
Darren J. Stefanyshyn
Keyword(s):  
Large Scale ◽  
Road Surface ◽  
Testing System ◽  
Male Athletes ◽  
Asphalt Road ◽  
Traction Testing ◽  
Maximal Effort

The outsole of a running shoe must provide enough traction for the athlete to avoid slipping during running. What is unknown is whether there is any point to designing running shoe outsoles with traction above this minimum required traction. The purpose of this study was to investigate whether performance could be enhanced by increasing the outsole traction of a running shoe. A commercially available running shoe (Control) was compared against the same shoe model with the outsole modified with a higher traction rubber (High Traction). The available traction of each shoe was measured with a traction testing system. Twenty male athletes completed a maximal effort timed running course in both shoes on two different surfaces. When wearing the Control running shoe, the athletes were able to complete the course on an asphalt road surface at maximal effort without slipping. When completing the same course wearing the High Traction shoe, the subjects were able to perform the course even faster. Therefore, the results show that the role of running shoe outsole traction is not to merely provide adequate traction to avoid large scale slips, but can also help athletes enhance performance of high-traction tasks such as accelerations and changes in direction.

scholarly journals Flame Spread over Liquid Fuel on a Water Layer-Basic Research on Tsunami Fire

2017 ◽  
Vol 07 (01) ◽  
pp. 11-21 ◽  
Author(s):  
Shingo Kuwana ◽  
Hidekazu Tamizu ◽  
Akihiko Ito ◽  
Hiroyuki Torikai
Keyword(s):  
Flame Spread ◽  
Liquid Fuel ◽  
Basic Research ◽  
Water Layer

scholarly journals Diapycnal oxygen supply to the tropical North Atlantic oxygen minimum zone

2012 ◽  
Vol 9 (10) ◽  
pp. 14291-14325 ◽  
Author(s):  
T. Fischer ◽  
D. Banyte ◽  
P. Brandt ◽  
M. Dengler ◽  
G. Krahmann ◽  
...  
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
Oxygen Supply ◽  
Water Layer ◽  
Oxygen Minimum Zone ◽  
Depth Interval ◽  
Diapycnal Mixing ◽  
Tropical North Atlantic ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. The replenishment of consumed oxygen in the open ocean oxygen minimum zone (OMZ) off West Africa in the tropical North Atlantic Ocean is studied, with a focus on oxygen transport across density surfaces (diapycnal flux). The latter is obtained from a large observational set of oxygen profiles and diapycnal mixing data from years 2008 to 2010. Diapycnal mixing is inferred from different sources: a large scale tracer release experiment, microstructure profiles, and shipboard acoustic current measurements plus density profiles. The average diapycnal diffusivity in the study area is 1 × 10−5 m2 s−1. No significant vertical gradient of average diapycnal diffusivities exists in the depth interval from 150 to 500 m. The diapycnal flux is found to contribute substantially to the oxygen supply of the OMZ. Within the OMZ core, 1.5 µmol kg−1 a−1 of oxygen is supplied via diapycnal mixing, contributing about a third of the total demand. The oxygen that is contributed via diapycnal mixing originates from oxygen that has been laterally supplied within the overlying Central Water layer by advective and eddy fluxes. Due to the existence of a separate shallow oxygen minimum at about 100 m depth throughout most of the study area, there is no direct net vertical oxygen flux from the surface layer of the study area into the Central Water layer. Thus all oxygen supply of the OMZ is associated with remote pathways.

THE LOSS OF A GRAIN FUMIGANT MIXTURE OF CARBON TETRACHLORIDE AND CARBON BISULFIDE THROUGH SEALING AND VARIOUS COVERING MATERIALS

1987 ◽  
Vol 119 (6) ◽  
pp. 595-597
Author(s):  
S.R. Loschiavo ◽  
N.D.G. White
Keyword(s):  
Carbon Tetrachloride ◽  
Large Scale ◽  
Room Temperature ◽  
Fire Hazard ◽  
Stored Products ◽  
Stored Grain ◽  
The World ◽  
The Usa ◽  
Carbon Bisulfide ◽  
Low Toxicity

Fumigants that are liquid formulations at room temperature have been widely used to kill insects in stored products, containers, and soil. Carbon bisulfide was one of the first fumigants used on a large scale as early as 1869 and is still the main fumigant used in some parts of the world (Bond 1984). Carbon bisulfide is highly flammable (Fleming and Baker 1935) and is usually formulated with carbon tetrachloride to aid distribution of fumigants in grain masses (Berck 1958) and to reduce the fire hazard. Although carbon tetrachloride is of low toxicity to insects it causes extensive liver damage in humans (Rouiller 1964). Liquid fumigants were widely used to disinfest stored grain in the USA until recently (White et al. 1985), and are still used in many other parts of the world (FA0 1985).

scholarly journals Combined measurement of velocity and temperature in liquid metal convection

2019 ◽  
Vol 876 ◽  
pp. 1108-1128 ◽  
Author(s):  
Till Zürner ◽  
Felix Schindler ◽  
Tobias Vogt ◽  
Sven Eckert ◽  
Jörg Schumacher
Keyword(s):  
Reynolds Number ◽  
Liquid Metal ◽  
Large Scale ◽  
Scale Up ◽  
Convection Cell ◽  
Small Scale ◽  
Convection Flow ◽  
Large Scale Circulation ◽  
Large Scale Flow ◽  
The Impact

Combined measurements of velocity components and temperature in a turbulent Rayleigh–Bénard convection flow at a low Prandtl number of $Pr=0.029$ and Rayleigh numbers of $10^{6}\leqslant Ra\leqslant 6\times 10^{7}$ are conducted in a series of experiments with durations of more than a thousand free-fall time units. Multiple crossing ultrasound beam lines and an array of thermocouples at mid-height allow for a detailed analysis and characterization of the complex three-dimensional dynamics of the single large-scale circulation roll in a cylindrical convection cell of unit aspect ratio which is filled with the liquid metal alloy GaInSn. We measure the internal temporal correlations of the complex large-scale flow and distinguish between short-term oscillations associated with a sloshing motion in the mid-plane as well as varying orientation angles of the velocity close to the top/bottom plates and the slow azimuthal drift of the mean orientation of the roll as a whole that proceeds on a time scale up to a hundred times slower. The coherent large-scale circulation drives a vigorous turbulence in the whole cell that is quantified by direct Reynolds number measurements at different locations in the cell. The velocity increment statistics in the bulk of the cell displays characteristic properties of intermittent small-scale fluid turbulence. We also show that the impact of the symmetry-breaking large-scale flow persists to small-scale velocity fluctuations thus preventing the establishment of fully isotropic turbulence in the cell centre. Reynolds number amplitudes depend sensitively on beam-line position in the cell such that different definitions have to be compared. The global momentum and heat transfer scalings with Rayleigh number are found to agree with those of direct numerical simulations and other laboratory experiments.

scholarly journals Road Surface Condition Forecasting in France

2009 ◽  
Vol 48 (12) ◽  
pp. 2513-2527 ◽  
Author(s):  
L. Bouilloud ◽  
E. Martin ◽  
F. Habets ◽  
A. Boone ◽  
P. Le Moigne ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Initial Conditions ◽  
Meteorological Data ◽  
Surface Condition ◽  
Road Surface ◽  
Snow Layer ◽  
Surface Conditions ◽  
The Road ◽  
Road Surface Temperature ◽  
On The Road

Abstract A numerical model designed to simulate the evolution of a snow layer on a road surface was forced by meteorological forecasts so as to assess its potential for use within an operational suite for road management in winter. The suite is intended for use throughout France, even in areas where no observations of surface conditions are available. It relies on short-term meteorological forecasts and long-term simulations of surface conditions using spatialized meteorological data to provide the initial conditions. The prediction of road surface conditions (road surface temperature and presence of snow on the road) was tested at an experimental site using data from a comprehensive experimental field campaign. The results were satisfactory, with detection of the majority of snow and negative road surface temperature events. The model was then extended to all of France with an 8-km grid resolution, using forcing data from a real-time meteorological analysis system. Many events with snow on the roads were simulated for the 2004/05 winter. Results for road surface temperature were checked against road station data from several highways, and results for the presence of snow on the road were checked against measurements from the Météo-France weather station network.

Experiment Study on Dynamic Response of Rough AC Surface under Vehicle

2011 ◽  
Vol 243-249 ◽  
pp. 4366-4372
Author(s):  
Guang Hai Zhang ◽  
Hai Gui Kang ◽  
Yuan Xun Zheng
Keyword(s):  
Service Life ◽  
Dynamic Response ◽  
Structural Design ◽  
Asphalt Pavement ◽  
Road Surface ◽  
Dynamic Responses ◽  
Experiment Study ◽  
Asphalt Road

In order to study dynamic response of rough road surface resulting from different speeds and loads under a certain roughness for purpose of effective enhancement pertinence for structural design of an asphalt pavement and extension of its service life, displacement meters, stress meters and strain meters are embedded at different structural layers on the rough road surface to monitor the dynamic responses of AC pavement. The result shows that roughness can dramatically increase response on an asphalt road surface resulting from load and speed.

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