scholarly journals Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag

2009 ◽  
Vol 9 (4) ◽  
pp. 14713-14733 ◽  
Author(s):  
S. R. Freitas ◽  
K. M. Longo ◽  
J. Trentmann ◽  
D. Latham
Keyword(s):  
Amazon Basin ◽  
Ambient Air ◽  
Atmospheric Model ◽  
Technical Note ◽  
Atmospheric Environment ◽  
Horizontal Wind ◽  
Plume Rise ◽  
Additional Increase ◽  
Smoke Plume ◽  
D Model

Abstract. We revisit the parameterization of the vertical transport of hot gases and particles emitted from biomass burning, described in Freitas et al. (2007), to include the effects of environmental wind on transport and dilution of the smoke plume at the cloud scale. Typically, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to explicitly simulate the time evolution of the plume rise with the additional mass and momentum. One-dimensional (1-D) model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three dimensional (3-D) Active Tracer High resolution Atmospheric Model (ATHAM). We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

scholarly journals Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag

2010 ◽  
Vol 10 (2) ◽  
pp. 585-594 ◽  
Author(s):  
S. R. Freitas ◽  
K. M. Longo ◽  
J. Trentmann ◽  
D. Latham
Keyword(s):  
Amazon Basin ◽  
Combustion Process ◽  
Ambient Air ◽  
Atmospheric Environment ◽  
Horizontal Wind ◽  
Plume Rise ◽  
Additional Increase ◽  
Smoke Plume ◽  
Vegetation Fires ◽  
D Model

Abstract. Vegetation fires emit hot gases and particles which are rapidly transported upward by the positive buoyancy generated by the combustion process. In general, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. In this paper, we revisit the parameterization of the vertical transport of hot gases and particles emitted from vegetation fires, described in Freitas et al. (2007), to include the effects of environmental wind on transport and dilution of the smoke plume at its scale. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to simulate the time evolution of the plume rise and the smoke injection height. One-dimensional (1-D) model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three-dimensional (3-D) Active Tracer High resolution Atmospheric Model (ATHAM). We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

scholarly journals Important parameters for smoke plume rise simulation with Daysmoke

2010 ◽  
Vol 1 (4) ◽  
pp. 250-259 ◽  
Author(s):  
Yongqiang Liu ◽  
Gary L. Achtemeier ◽  
Scott L. Goodrick ◽  
William A. Jackson
Keyword(s):  
Plume Rise ◽  
Smoke Plume

Validation of smoke plume rise models using ground-based Lidar

2014 ◽  
Author(s):  
V. Kovalev ◽  
S. Urbanski ◽  
A. Petkov ◽  
A. Scalise ◽  
C. Wold ◽  
...  
Keyword(s):  
Plume Rise ◽  
Smoke Plume ◽  
Ground Based Lidar

scholarly journals Capturing Plume Rise and Dispersion with a Coupled Large-Eddy Simulation: Case Study of a Prescribed Burn

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 579
Author(s):  
Nadya Moisseeva ◽  
Roland Stull
Keyword(s):  
Large Eddy Simulation ◽  
Numerical Models ◽  
Real Life ◽  
Plume Rise ◽  
Atmospheric Conditions ◽  
Prescribed Burn ◽  
Smoke Plume ◽  
Fire Emissions ◽  
Eddy Simulation ◽  
Large Eddy

Current understanding of the buoyant rise and subsequent dispersion of smoke due to wildfires has been limited by the complexity of interactions between fire behavior and atmospheric conditions, as well as the uncertainty in model evaluation data. To assess the feasibility of using numerical models to address this knowledge gap, we designed a large-eddy simulation of a real-life prescribed burn using a coupled semi-emperical fire–atmosphere model. We used observational data to evaluate the simulated smoke plume, as well as to identify sources of model biases. The results suggest that the rise and dispersion of fire emissions are reasonably captured by the model, subject to accurate surface thermal forcing and relatively steady atmospheric conditions. Overall, encouraging model performance and the high level of detail offered by simulated data may help inform future smoke plume modeling work, plume-rise parameterizations and field experiment designs.

scholarly journals Modeling Smoke Plume-Rise and Dispersion from Southern United States Prescribed Burns with Daysmoke

Atmosphere ◽  
2011 ◽  
Vol 2 (3) ◽  
pp. 358-388 ◽  
Author(s):  
Gary L. Achtemeier ◽  
Scott A. Goodrick ◽  
Yongqiang Liu ◽  
Fernando Garcia-Menendez ◽  
Yongtao Hu ◽  
...  
Keyword(s):  
United States ◽  
Southern United States ◽  
Plume Rise ◽  
Prescribed Burns ◽  
Smoke Plume

Study of Smoke Stratification in Atrium Halls Using Scale Model

2009 ◽  
Author(s):  
N. K. Fong ◽  
C. H. Ko
Keyword(s):  
Air Temperature ◽  
Detection System ◽  
National Fire Protection Association ◽  
Ambient Air ◽  
Scale Model ◽  
Triangular Prism ◽  
Smoke Movement ◽  
Smoke Plume ◽  
Smoke Layer ◽  
Plume Temperature

Nowadays, atrium building is very popular because it can provide extensity and attraction to the users even if they are inside the enclosed environment. Similar to other buildings, fire safety is one of the major concerns especially the atrium are linked to shopping arcades. The major challenge is to control the smoke movement in the case of fire and maintain a stable smoke layer clear height to allow sufficient time for the occupants to evacuate from the building. Therefore, an efficient smoke management system (SMS) is necessary. For the SMS to function properly, the smoke behaviour inside the atrium must be studied. One of the phenomena affecting the operation of the SMS is smoke stratification. That is, due to the vertical temperature gradient inside the atrium, a thermally stratified environment is formed and smoke will not be able to reach the smoke detectors/smoke outlets in the ceiling. In the past decade, various studies were conducted to study the smoke filling process in the atrium. Only a few studies were carried out to study smoke stratification in atrium. This paper attempted to study the factors leading to the development of thermally stratified environment in an atrium and the formation of smoke stratification under the ceiling space of an atrium building using scale model. These factors included the temperature of the smoke plume, the air temperature under the ceiling, the configuration of roof ceiling and the ambient air temperature. Two types of ceiling configurations such as a cuboid and a triangular prism are used. Data concerning the ceiling air temperature, smoke plume temperature, effect of different ceiling configuration and maximum smoke layer height in a thermally stratified environment are collected. Comparisons are conducted with the calculated results from National Fire Protection Association (NFPA) 92B equations. With all these information, better design criteria of smoke detection system, SMS in an atrium building can be developed. Finally, the experimental results can be used to investigate the discrepancies between the experimental measurement and the calculated results from NFPA 92B equations. Put abstract text here.

scholarly journals Thermospheric winds and temperatures above Mawson, Antarctica, observed with an all-sky imaging, Fabry-Perot spectrometer

2009 ◽  
Vol 27 (5) ◽  
pp. 2225-2235 ◽  
Author(s):  
C. Anderson ◽  
M. Conde ◽  
P. Dyson ◽  
T. Davies ◽  
M. J. Kosch
Keyword(s):  
Large Scale ◽  
Atmospheric Model ◽  
Horizontal Wind ◽  
Data Set ◽  
Average Behavior ◽  
Wind Speeds ◽  
Zonal Winds ◽  
F Region ◽  
Fabry Perot ◽  
Thermospheric Winds

Abstract. A new all-sky imaging Fabry-Perot spectrometer has been installed at Mawson station (67°36' S, 62°52' E), Antarctica. This instrument is capable of recording independent spectra from many tens of locations across the sky simultaneously. Useful operation began in March 2007, with spectra recorded on a total of 186 nights. Initial analysis has focused on the large-scale daily and average behavior of winds and temperatures derived from observations of the 630.0 nm airglow line of atomic oxygen, originating from a broad layer centered around 240 km altitude, in the ionospheric F-region. The 1993 Horizontal Wind Model (HWM93), NRLMSISE-00 atmospheric model, and the Coupled Thermosphere/Ionosphere Plasmasphere (CTIP) model were used for comparison. During the geomagnetically quiet period studied, observed winds and temperatures were generally well modelled, although temperatures were consistently higher than NRLMSISE-00 predicted, by up to 100 K. CTIP temperatures better matched our data, particularly later in the night, but predicted zonal winds which were offset from those observed by 70–180 ms−1 westward. During periods of increased activity both winds and temperatures showed much greater variability over time-scales of less than an hour. For the active night presented here, a period of 45 min saw wind speeds decrease by around 180 ms−1, and temperatures increase by approximately 100 K. Active-period winds were poorly modelled by HWM93 and CTIP, although observed median temperatures were in better agreement with NRLMSISE-00 during such periods. Average behavior was found to be generally consistent with previous studies of thermospheric winds above Mawson. The collected data set was representative of quiet geomagnetic and solar conditions. Geographic eastward winds in the afternoon/evening generally continued until around local midnight, when winds turned equatorward. Geographic meridional and zonal winds in the afternoon were approximately 50 ms−1 weaker than expected from HWM93, as was the transition to equatorward flow around midnight. There was also a negligible geographic zonal component to the post-midnight wind where HWM93 predicted strong westward flow. Average temperatures between 19:00 and 04:00 local solar time were around 60 K higher than predicted by NRLMSISE-00.

scholarly journals Evaluation of wildland fire smoke plume dynamics and aerosol load using UV scanning lidar and fire–atmosphere modelling during the Mediterranean Letia 2010 experiment

2014 ◽  
Vol 14 (3) ◽  
pp. 509-523 ◽  
Author(s):  
V. Leroy-Cancellieri ◽  
P. Augustin ◽  
J. B. Filippi ◽  
C. Mari ◽  
M. Fourmentin ◽  
...  
Keyword(s):  
Wildland Fire ◽  
Mediterranean Area ◽  
Atmospheric Model ◽  
Vertical Position ◽  
Passive Tracer ◽  
Smoke Plume ◽  
Fire Propagation ◽  
Lidar Measurements ◽  
Fire Smoke ◽  
Scanning Lidar

Abstract. Vegetation fires emit large amount of gases and aerosols which are detrimental to human health. Smoke exposure near and downwind of fires depends on the fire propagation, the atmospheric circulations and the burnt vegetation. A better knowledge of the interaction between wildfire and atmosphere is a primary requirement to investigate fire smoke and particle transport. The purpose of this paper is to highlight the usefulness of an UV scanning lidar to characterise the fire smoke plume and consequently validate fire–atmosphere model simulations. An instrumented burn was conducted in a Mediterranean area typical of ones frequently subject to wildfire with low dense shrubs. Using lidar measurements positioned near the experimental site, fire smoke plume was thoroughly characterised by its optical properties, edge and dynamics. These parameters were obtained by combining methods based on lidar inversion technique, wavelet edge detection and a backscatter barycentre technique. The smoke plume displacement was determined using a digital video camera coupled with the lidar. The simulation was performed using a mesoscale atmospheric model in a large eddy simulation configuration (Meso-NH) coupled to a fire propagation physical model (ForeFire), taking into account the effect of wind, slope and fuel properties. A passive numerical scalar tracer was injected in the model at fire location to mimic the smoke plume. The simulated fire smoke plume width remained within the edge smoke plume obtained from lidar measurements. The maximum smoke injection derived from lidar backscatter coefficients and the simulated passive tracer was around 200 m. The vertical position of the simulated plume barycentre was systematically below the barycentre derived from the lidar backscatter coefficients due to the oversimplified properties of the passive tracer compared to real aerosol particles. Simulated speed and horizontal location of the plume compared well with the observations derived from the videography and lidar method, suggesting that fire convection and advection were correctly taken into account.

Line Plume Approximation on Atrium Smoke Filling With Thermal Stratified Environment

2003 ◽  
Vol 125 (2) ◽  
pp. 289-300 ◽  
Author(s):  
J. Li ◽  
W. K. Chow
Keyword(s):  
Plume Rise ◽  
Upward Motion ◽  
Smoke Plume ◽  
Air Density ◽  
Smoke Filling ◽  
Balcony Spill Plume

Upward motion of a balcony spill plume in an atrium with a thermal stratified layer will be simulated. This is aimed at answering the question on whether a smoke plume can move up an atrium to reach the ceiling. The gradient of air density in the atrium is taken as a constant negative value. The plume motion under this condition is compared with the case without a thermal stratified layer. It is noted that the effect of stratification is not obvious in regions near to the fire. But for the upper region of the plume, the effect is significant. In this way, the plume might not be able to reach the ceiling of an atrium with a hot enough thermal stratified layer. The maximum plume rise under this condition will also be calculated.

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