Experimental investigation of fire propagation in single live shrubs

2017 ◽  
Vol 26 (1) ◽  
pp. 58 ◽  
Author(s):  
Jing Li ◽  
Shankar Mahalingam ◽  
David R. Weise
Keyword(s):  
Wind Speed ◽  
Mass Loss ◽  
Bulk Density ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Flame Height ◽  
Maximum Mass ◽  
Gas Temperature ◽  
Fire Behaviour ◽  
Maximum Mass Loss

This work focuses broadly on individual, live shrubs and, more specifically, it examines bulk density in chaparral and its combined effects with wind and ignition location on the resulting fire behaviour. Empirical functions to predict bulk density as a function of height for 4-year-old chaparral were developed for two typical species of shrub fuels in southern California, USA, namely chamise (Adenostoma fasciculatum Hook & Arn.) and manzanita (Arctostaphylos spp. Adans.). Fuel beds of chamise foliage and small-diameter branches were burned in an open-topped wind tunnel. Three levels of bulk density, two ignition locations and two wind speeds were examined, focusing on overall fire behaviour. Mean maximum mass loss rate, elapsed time at which maximum mass loss rate occurred, flame height, flame angle, peak gas temperature and its peak change rate were measured. The mean maximum mass loss rate was not significantly affected by wind speed, ignition location, bulk density or moisture content. Both wind speed and ignition location significantly affected the time that maximum mass loss rate occurred. Only wind speed affected flame height and flame angle. The peak gas temperature within the shrub burning area was found to be mostly affected by the bulk density.

scholarly journals Author Correction: Reduction of the maximum mass-loss rate of OH/IR stars due to unnoticed binary interaction

2019 ◽  
Vol 3 (5) ◽  
pp. 462-462
Author(s):  
L. Decin ◽  
W. Homan ◽  
T. Danilovich ◽  
A. de Koter ◽  
D. Engels ◽  
...  
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Binary Interaction ◽  
Maximum Mass ◽  
Ir Stars ◽  
Maximum Mass Loss

scholarly journals Reduction of the maximum mass-loss rate of OH/IR stars due to unnoticed binary interaction

2019 ◽  
Vol 3 (5) ◽  
pp. 408-415 ◽  
Author(s):  
L. Decin ◽  
W. Homan ◽  
T. Danilovich ◽  
A. de Koter ◽  
D. Engels ◽  
...  
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Binary Interaction ◽  
Maximum Mass ◽  
Ir Stars ◽  
Maximum Mass Loss

Effect of Sample Width on Downward Flame Spread over Typical Energy Conservation Material at a High Elevation Area

2014 ◽  
Vol 664 ◽  
pp. 199-203 ◽  
Author(s):  
Wei Guang An ◽  
Lin Jiang ◽  
Jin Hua Sun ◽  
K.M. Liew
Keyword(s):  
Mass Loss ◽  
Flame Spread ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
High Elevation ◽  
Flame Height ◽  
Spread Rate ◽  
Flame Spread Rate ◽  
Sample Width ◽  
Downward Flame Spread

An experimental study on downward flame spread over extruded polystyrene (XPS) foam at a high elevation is presented. The flame shape, flame height, mass loss rate and flame spread rate were measured. The influences of width and high altitude were investigated. The flame fronts are approximately horizontal. Both the intensity of flame pulsation and the average flame height increase with the rise of sample width. The flame spread rate first drops and then rises with an increase in width. The average flame height, mass loss rate and flame spread rate at the higher elevation is smaller than that at a low elevation, which demonstrates that the XPS fire risk at the higher elevation area is lower. The experimental results agree well with the theoretical analysis. This work is vital to the fire safety design of building energy conservation system.

Effect of Sample Width on Characteristics of Flame Spread across Eucalyptus Wood Surface

2013 ◽  
Vol 401-403 ◽  
pp. 767-770
Author(s):  
Gui Hong Wu ◽  
Yi Qiang Wu ◽  
Yun Chu Hu ◽  
Xiao Dan Zhu
Keyword(s):  
Mass Loss ◽  
Flame Spread ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Flame Height ◽  
Spread Rate ◽  
Eucalyptus Wood ◽  
Flame Spread Rate ◽  
Sample Width ◽  
The Relationship

To study the effect of sample width on flame spread characteristics, a series of laboratory-scale experiments were conducted employing eucalyptus wood with width from 3 to 7 cm. Flame dimension, flame spread rate and mass loss rate were obtained. The relationship between these flame spread characteristics and sample width was explored. Both the dimensionless average flame height and depth vary as the-n power of sample width. With the increase of sample width, both the flame spread rate and mass loss rate first decrease and then rise. The minimum values appear when sample width measures 6 cm.

Experimental Study on Downward Flame Spread across XPS Surface

2013 ◽  
Vol 753-755 ◽  
pp. 445-451
Author(s):  
Wei Guang An ◽  
Hua Hua Xiao ◽  
Jin Hua Sun ◽  
Wei Gang Yan ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Mass Loss ◽  
Flame Spread ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Flame Height ◽  
Spread Rate ◽  
Flame Spread Rate ◽  
Stage 1 ◽  
Exponential Change ◽  
Downward Flame Spread

To study downward flame spread across XPS surface, a series of laboratory-scale experiments were conducted. Typical flame spread characteristics were obtained. The flame spread process comprises four stages. There are twice accelerations during flame spread. The influence of maximum flame height on flame spread rate is not significant. The predicted flame spread rate utilizing mass loss rate is lower than the measured value. Three stages: increasing stage, stable stage and decreasing stage are observed in both change of maximum flame height and flame area. The changing trend of mass loss rate is similar to that of maximum flame height. For stage 1 and stage 3, exponential change of mass loss rate with time is found. The mass loss rate is constant for stage 2. The heat flux to the preheating zone is higher than that to surrounding environment. Experimental results agree well with theoretical analysis.

Applicability of FLASH-CAT Model to Cable Tray Fire Modeling in Zone Model BRI2002

2020 ◽  
Author(s):  
Koji Shirai ◽  
Koji Tasaka ◽  
Toshiko Udagawa
Keyword(s):  
Mass Loss ◽  
Large Scale ◽  
Fire Test ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Zone Model ◽  
Gas Temperature ◽  
Fire Source ◽  
Gas Burner ◽  
Tray Fire

Abstract To clarify the heat and smoke propagation in multi-compartments under the spread of cable fire, a large-scale multi-compartment fire test (hereinafter the CFS-2 test) was performed by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in France within the framework promoted by the Nuclear Energy Agency (NEA) in Organization for Economic Co-operation and Development (OECD) program PRISME2 (OECD/NEA, 2017). In the CFS-2 test, two rooms of a large-scale facility were adopted and these rooms have an identical volume (120 m3) enclosed with fire walls and were connected by a doorway (0.8 m in width and 2.17 m in height). As a fire source, five-layer cable trays (tray length of 2.4m, tray width of 0.45m and separation distance between trays of 0.3 m) with a fire-retardant PVC cable (77 kg) were used and ignited by a propane gas burner. The power level of the propane gas burner was set to around 80 kW. Moreover, all rooms were mechanically ventilated, and the renewal rate was 15 times per hour (3600 m3/h). During the fire test, the mass loss rate of fuel, gas and soot mass concentration, gas temperature, and etc. were measured. The measured peak values of the HRR, the mass loss rate and gas temperature were about 800 kW, 58 g/s and greater than 600 °C, respectively (Zavaleta, 2017). As a fire model predicting fire characteristics in a compartment, a two-zone model, which divides the fire room into the hot smoke upper layer and lower layer consisting of cool fresh air, is widely used due to the advantages of the brevity of the calculation routine and the reliability of the calculation results. Among them, the BRI2 series, developed in Japan, is now reaching the current BRI2002 software (Wakamatsu, 2004) after several upgrades to improve the calculation precision. The Central Research Institute of Electric Power Industry (CRIEPI) introduced the cable tray fire source model based on the FLASH-CAT (Flame Spread over Horizontal Cable Trays) developed by National Institute of Standards and Technology (NIST) (McGrattan, 2012) into the zone code BRI2002. By comparing the numerical results with the experimental values measured during the CFS-2 test, the methodology for ignition time delay of each tray and horizontal flame propagation speed for each tray were discussed.

scholarly journals The estimate of hot Jupiter mass loss rate in the interaction with CME from a solar type star

2015 ◽  
Vol 11 (S320) ◽  
pp. 224-229
Author(s):  
Dmitry V. Bisikalo ◽  
Alexander A. Cherenkov ◽  
Pavel V. Kaygorodov
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Type Star ◽  
Dynamic Simulations ◽  
Solar Type ◽  
Mass Ejection ◽  
Maximum Mass Loss ◽  
Solar Type Star ◽  
Hot Jupiter

AbstractWe consider the influence of a coronal mass ejection (CME) of a solar type star on the mass loss rate of a hot Jupiter exoplanet. We have conducted 3D numerical gas-dynamic simulations of the planet's atmosphere that interacts with CME. Using the results of these simulations we have estimated the specific parameters that influence the mass loss rate. Based on the assumption that CME totally sweeps away part of the planet's gaseous envelope located outside the Roche lobe we estimated the maximum mass loss rate. Finally, we have considered the dependence of mass loss rate on the frequency of CMEs in course of star's evolution.

Evolution of pool fire plume characteristics during the depressurization process of an aircraft cargo compartment

2018 ◽  
Vol 36 (4) ◽  
pp. 362-375 ◽  
Author(s):  
Cong Li ◽  
Rui Yang ◽  
Yina Yao ◽  
Zhenxiang Tao ◽  
Hui Zhang
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Ambient Air ◽  
Pool Fire ◽  
Flame Height ◽  
Fire Plume ◽  
Activation Effect ◽  
Centerline Temperature ◽  
Ventilation Factor

This article presents an experimental investigation on the pool fire plume characteristics in a full-scale depressurized aircraft cargo compartment. The effects of decreasing pressure and vent flow rate on the fire characteristics such as flame shape, flame puffing, flame height, and centerline temperature were analyzed. The results show that during the depressurization process, the ventilation had an activation effect on the mass loss rate, and its increment had a linear relationship with the dimensionless ventilation factor. In addition, the larger depressurized rate caused the larger dimensionless ventilation factor and further resulted in the larger increment of mass loss rate. The flame puffing frequency was determined by the ratio of the gas density in the flame area of that in the ambient air, which increased with the drop of pressure. For flame centerline temperature, there was a counteraction area in the flame intermittent region, where the centerline temperature had almost no difference before and after the depressurization. The conclusions could provide the theoretical base and reference materials for the fire disaster in the cargo compartment of real aircrafts.

Correlation of rate of gas temperature rise with mass loss rate in a ceiling vented compartment

2014 ◽  
Vol 59 (33) ◽  
pp. 4559-4567 ◽  
Author(s):  
Ruiyu Chen ◽  
Shouxiang Lu ◽  
Bosi Zhang ◽  
Changhai Li ◽  
Siuming Lo
Keyword(s):  
Mass Loss ◽  
Temperature Rise ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Gas Temperature

scholarly journals AGB mass loss

2011 ◽  
Vol 7 (S283) ◽  
pp. 71-78
Author(s):  
Lee A. Willson ◽  
Qian Wang
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Central Star ◽  
Constant Mass ◽  
Single Star ◽  
The Core ◽  
Maximum Mass Loss ◽  
Loss Formula ◽  
Remnant Mass

AbstractMass loss on the AGB removes most of the envelope and leaves a compact remnant to become a white dwarf and perhaps first the central star of a planetary nebula. The envelope mass provides an upper limit on the material available to form the PN, and the terminal mass loss rate plus the small remnant mass left on the core determines how much of that would still be available to form the PN after the star has evolved far enough to the blue. Given a mass loss formula based on observations or models, we can find the deathline where −dMstar/dt = (M/L) dL/dt and can find the contours of constant mass loss rate on a plot of M vs. L. From such plots we can derive the mass available for a PN and the lowest mass single star that can produce a PN of a given mass. However, some details important for PN formation remain uncertain, including the maximum mass loss rate achieved and the envelope mass left when AGB mass loss ceases.

Sign in / Sign up

Export Citation Format

Share Document