Author: J. J. TrellesPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Smoke Dispersion From Multiple Fire Plumes
Author: J. J. TrellesSmoke Dispersion from Multiple Fire Plumes
Author: Howard R. BaumPublisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
The effects of multiple fire plumes in a stably stratified atmosphere with a uniform wind are investigated. A parabolized approximation of the steady-state Navier-Stokes equations obtained by replacing the windward velocity component with the ambient wind speed is the basis of the model. Lagrangian particles are used to visualize the flow, account for atmospheric fluctuations, and determine the smoke concentration field. Multiple-plume interactions can push particulate up to altitudes exceeding that of an equivalent single plume. A parametric study based on separation and heat release rates is performed for two plumes. The most dramatic increases in plume rise and spread are found for in-line plumes, parallel to the wind direction. Multiple-plume interactions can yield nonuniformities in the smoke concentration field that differ substantially from that predicted by Gaussian models.
Atmospheric Dispersion of Smoke Plumes Produced from Large Tire Fires
Author: Michael J. RzeznikSmoke Dispersion Model for Prescribed Burning
Author: James A. PharoPublisher:
ISBN:
Category : Prescribed burning
Languages : en
Pages : 8
Book Description
Journal of Research of the National Institute of Standards and Technology
Author: Characterization of Smoke Plume Emissions and Dynamics from Prescribed and Wildland Fires Using High-resolution Field Observations and a Coupled Fire-atmosphere Model
Author: Kara M. YedinakPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Smoke plumes associated with wildland fires are difficult to characterize due to the non-linear behavior of the variables involved. Plume chemistry is largely modeled using emission factors to represent the relative trace gas and aerosol species emitted. Plume dynamics are modeled based on assumptions of plume vertical distribution and atmospheric dispersion. In the studies presented here, near and in-source measurements of emissions from prescribed burns are used to characterize the variability of emission factors from low-intensity fires. Emissions factors were found to be in the same range as those from other, similar studies in the literature and it appears that the emission factors may be sensitive to small differences in surface conditions such as fuel moisture, surface wind speed, and the ratio of live to dead fuels. We also used two coupled fire atmosphere models, which utilize the Weather Research and Forecasting (WRF) model called WRF-Fire and WRF-Sfire, to investigate the role that atmospheric stability plays in influencing plume rise as well as developing a technique for assessing plume rise and the vertical distribution of pollutants in regional air quality models. Plume heights, as well as rate of growth of the fire, were found to be sensitive to atmospheric stability while fire rate of spread was not. The plume center-of-mass technique was demonstrated to work well but has slightly low estimates compared to observations.
Climate Change, Air Pollution and Global Challenges
Author: Mikhail SofievPublisher: Elsevier Inc. Chapters
ISBN: 0128055731
Category : Nature
Languages : en
Pages : 23
Book Description
The chapter gives a short outlook of wildland fires and their influence on atmospheric composition, air quality and climate. Fires are among the most powerful sources of atmospheric tracers and also means of changing the ecosystems themselves. Present pattern of the biomass burning is strongly affected by anthropogenic activities, both via accidental and deliberate ignitions of the fires (about 90% fires are started by humans) and via various fire-fighting and prevention measures. The role of urban–rural interface territories is particularly high in this regard. The fire specifics and impact vary in the different parts of the globe. In forested regions, the bulk of consumed biomass can be attributed to a comparatively small number of major episodes, whereas in arid regions, individual fires are smaller but more numerous. Remote sensing is the primary way of fire monitoring. Three types of products—inventories of burnt areas, count of active fires and estimates of release of fire radiative energy—are available from several satellite instruments. Altogether, they cover the whole globe and span over several decades. Based on this information, several inventories of consumed biomass and atmospheric emissions have been compiled. Their comparison shows qualitative similarity of the products but the differences are substantial. Understanding the reasons for these differences and development of consensus-based methodologies is among the main challenges for the near future.
Dispersion of Slash Fire Smoke Plumes
Author: Elmer RobinsonSmoke Dispersal from a Controlled Fire in Logging Debris Over a Cleared Pine Forest Area
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The dispersion of smoke in the atmosphere was studied during a controlled fire of forest debris. An instrumented aircraft measured smoke density and other parameters in multiple traverses through the smoke plume. The data permitted contour maps of constant smoke density to be drawn in three dimensions. Centerline smoke density reached a maximum of 0.43 .mu.g/m3. Supporting meteorological data were taken at an array of towers (7 towers, each 62 meters high) near the fire, and at different elevations on a TV tower (400 meters high) located 35 km from the site of the fire. The data will permit the testing of mathematical models for the prediction of the dispersion of pollutants in the atmosphere.
Author: