scholarly journals MATHEMATICAL MODELING OF THE FOREST FIRE IMPACT ON THE BRANCH OF A CONIFEROUS TREE

2021 ◽  
Vol 4 (2) ◽  
pp. 1-15
Author(s):  
N.V. Baranovskiy ◽  
◽  
D. S. Menshikov ◽  
Keyword(s):  
Mathematical Modeling ◽  
Forest Fire ◽  
Quantitative Methods ◽  
Heat Propagation ◽  
Coniferous Tree ◽  
Flame Zone ◽  
Fire Front ◽  
Tree Branch ◽  
The Impact ◽  
The Mathematical Model

It is necessary to develop quantitative methods to assess the formation of thermal burns in the morphological parts of coniferous trees. The purpose of the study can be formulated as follows: mathematical modeling of heat transfer in the layered structure of a coniferous tree branch under the influence of a forest fire front. The heat propagation in the “branch-needles-flame zone” system is described by a system of non-stationary differential equations of heat conduction with the corresponding initial and boundary conditions. As an object of research, a digital model of a branch of a coniferous tree for various species, namely, pine, larch and fir, was used. Temperature distributions are obtained for different variants of the branch structure and conditions of the impact of the forest fire front. Conclusions are made about the need for further modernization of the mathematical model. The developed model is the basis for creating software tools for specialized geographic information systems.

scholarly journals Mathematical Modeling of Thermal Influence from Forest Fire Front on a Coniferous Tree Trunk

2016 ◽  
Vol 110 ◽  
pp. 01005 ◽  
Author(s):  
Nikolay V. Baranovskiy ◽  
Vladimir B. Barakhnin ◽  
Ksenia N. Andreeva
Keyword(s):  
Mathematical Modeling ◽  
Forest Fire ◽  
Coniferous Tree ◽  
Tree Trunk ◽  
Fire Front ◽  
Thermal Influence

Experimental assessment of the influence of radiant heat transfer on the transition of a crown fire to settlements

2021 ◽  
pp. 19-26
Author(s):  
Николай Петрович Копылов ◽  
Елена Юрьевна Сушкина ◽  
Александр Евгеньевич Кузнецов ◽  
Виктория Ивановна Новикова
Keyword(s):  
Heat Flow ◽  
Forest Fire ◽  
Fire Resistance ◽  
Fire Protection ◽  
Forest Fires ◽  
Radiant Heat ◽  
Radiant Heat Transfer ◽  
Crown Fire ◽  
Fire Front ◽  
The Impact

Проведены экспериментальные исследования влияния лучистого теплообмена на переход верхового лесного пожара на постройки IV и V степеней огнестойкости. Лесной верховой пожар моделировался горением штабеля древесины с интенсивностью тепловыделения, близкой к интенсивности при реальных пожарах. Получена зависимость изменения плотности теплового потока от расстояния до кромки горения. Экспериментально определены температура воздуха с подветренной стороны пожара и плотность выпадения искр в зависимости от расстояния. Проверена эффективность защиты растворами ретардантов деревянных строений от возгорания при лучистом теплообмене между факелом пламени пожара и объектом защиты. Crown fires are the main threat of the combustion transfer from the forest to objects located in it. Fire services dealing with forest fires face the problem how to protect these objects from forest fires. It is proposed to treat the object with retardant solutions before a forest fire approaches. To assess the effectiveness of such tactics for fire protection of objects when exposed to a heat flow from the combustion front there were carried out experiments on large-scale crown fire models. A crown fire is simulated with a pile of wood with a heat release rate of ≈ 13 MW m. The wind is generated by fans, its speed is close to the speed at which a forest fire occurs. Measurements of the heat flux density, medium temperature, and the density of sparks falling downwind of the fire front at different distances and heights were carried out. Calculations were carried out to assess the impact of heat flow on buildings of IV-V degrees of fire resistance. The results obtained are compared with experimental data and they are in good agreement. There have been determined the distances from the fire front at which the fire protection with retardant solutions is effective for structures of IV-V fire resistance degrees at radiant heat exchange.

scholarly journals Mathematical modeling of the impact of forest fires on buildings and structures

2018 ◽  
Vol 209 ◽  
pp. 00021
Author(s):  
Valeriy Perminov ◽  
Victoria Marzaeva
Keyword(s):  
Mathematical Modeling ◽  
Forest Fire ◽  
Forest Fires ◽  
Fire Behavior ◽  
Fire Intensity ◽  
Physical Mechanisms ◽  
Important Concern ◽  
Fire Initiation ◽  
The Impact ◽  
Fundamental Physical

The protection of buildings and structures in a community from destruction by forest fires is a very important concern. This paper addresses the development of a mathematical model for fires in the wildland-urban intermix. The forest fire is a very complicated phenomenon. At present, fire services can forecast the danger rating of, or the specific weather elements relating to, forest fire. There is need to understand and predict forest fire initiation, behavior and impact of fire on the buildings and constructions. This paper’s purposes are the improvement of knowledge on the fundamental physical mechanisms that control forest fire behavior. The mathematical modeling of forest fires actions on buildings and structures has been carried out to study the effects of fire intensity and wind speed on possibility of ignition of buildings.

Calculating and interpreting forest fire intensities

1982 ◽  
Vol 60 (4) ◽  
pp. 349-357 ◽  
Author(s):  
Martin E. Alexander
Keyword(s):  
Forest Fire ◽  
International System ◽  
Unit Length ◽  
Fire Behavior ◽  
Energy Output ◽  
Fire Intensity ◽  
Linear Rate ◽  
Fire Front ◽  
Quantitative Basis ◽  
The Impact

Frontal fire intensity is a valid measure of forest fire behavior that is solely a physical attribute of the fire itself. It is defined as the energy output rate per unit length of fire front and is directly related to flame size. Numerically, it is equal to the product of net heat of combustion, quantity of fuel consumed in the active combustion zone, and a spreading fire's linear rate of advance. The recommended International System (SI) units are kilowatts per metre. This concept of fire intensity provides a quantitative basis for fire description useful in evaluating the impact of fire on forest ecosystems.

scholarly journals Study of the process of preparing feeding mixtures using the composite mixer

2018 ◽  
Vol 5 (1) ◽  
pp. 17-22 ◽  
Author(s):  
M. Chernovol ◽  
M. Sviren ◽  
R. Kisiliov
Keyword(s):  
Mathematical Modeling ◽  
Slope Angle ◽  
Mixing Process ◽  
Solid Mass ◽  
Technological Parameters ◽  
Effi Ciency ◽  
Paddle Mixer ◽  
Working Bodies ◽  
The Impact ◽  
The Mathematical Model

Aim. Enhancing the quality and improving the technological process of mixing feeds using the new con- struction of the mixer and substantiating its rational parameters. Methods. Mathematical modeling theories, fundamentals of using machinery in animal breeding. Results. The estimated model of the functioning of a constructive-technological scheme of a composite mixer and the mathematical model of the dynamic interac- tion of mixer paddles and the solid mass of feeds were elaborated. It was established that the technological effi ciency of preparing the homogeneous mixture depends on physical and mechanic properties of its compo- nents, the impact and interaction between the form and geometric parameters of the attacking surface of the paddles, the slope angle, the setting increment and working modes of the mixer. Conclusions. The results of the studies confi rm the possibility of enhancing the effi ciency of the technology of preparing completely balanced feeding mixtures for cattle via the intensifi cation of the mixing process using the construction of the composite belt-paddle mixer, the elaboration of theoretical fundamentals of the interaction of feed components with the working bodies and substantiating their main constructive and technological parameters.

scholarly journals Mathematical Modeling of the Resistance of Pulling out Steel Bars from High Strength Concrete

2018 ◽  
Vol 7 (3.2) ◽  
pp. 516 ◽  
Author(s):  
Yevgenij Babych ◽  
Sergij Filipchuk ◽  
Oleksiy Fenko
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Steel Bars ◽  
Specific Factors ◽  
The Impact ◽  
Experimental Researches ◽  
The Mathematical Model

The article gives the results of the experimental researches of the bond between steel and high strength concrete. According to these results the mathematical model was built to define the boundary stresses of the bond between steel and concrete on their contact surface. The analysis of the impact of the specific factors on the boundary stresses of the bond between steel and concrete was carried out. 

scholarly journals Impact Force Magnitude Analysis of an Impact Pendulum Suspended in a Vibrating Structure

2012 ◽  
Vol 19 (6) ◽  
pp. 1359-1372 ◽  
Author(s):  
R.R. Aguiar ◽  
H.I. Weber
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Mathematical Model ◽  
Impact Force ◽  
Experimental Measurements ◽  
Force Magnitude ◽  
Force Profile ◽  
The Rich ◽  
The Impact ◽  
The Mathematical Model

The purpose of this work is the experimental investigation and the mathematical modeling of the impact force behavior in a vibro-impact system, where an impact pendulum is mounted on a cart that moves with a prescribed displacement. The dynamics of the system will be evaluated considering different excitation frequencies and changing the impact gap. Experimental data are used to validate the mathematical model. The mathematical model allows a detailed nonlinear analysis, showing the rich response of the system, which includes dynamical jumps, bifurcations and chaos. In impact systems, discrepancies between numerical results and experimental measurements are common due to the difficulty in describing all factors that influence the resulting impact force profile. The use of wires to suspend the impacting body has the purpose to limit these uncertainties.

scholarly journals Scenario Modeling of Thermal Influence from Forest Fire Front on a Coniferous Tree Trunk

2016 ◽  
Vol 72 ◽  
pp. 01008
Author(s):  
Nikolay V. Baranovskiy ◽  
Vladimir B. Barakhnin ◽  
Ksenia N. Andreeva
Keyword(s):  
Forest Fire ◽  
Coniferous Tree ◽  
Tree Trunk ◽  
Scenario Modeling ◽  
Fire Front ◽  
Thermal Influence

Numerical simulation of the tree higro-thermal response in forest fire environment

2020 ◽  
pp. 57-65
Author(s):  
Eusébio Conceiçã ◽  
João Gomes ◽  
Maria Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Xavier Viegas ◽  
...  
Keyword(s):  
Forest Fire ◽  
Numerical Study ◽  
Thermal Response ◽  
View Factor ◽  
Tree Model ◽  
Pine Tree ◽  
Surface Temperatures ◽  
Fire Environment ◽  
Fire Front ◽  
Heat Exchanges

This paper refers to a numerical study of the hypo-thermal behaviour of a pine tree in a forest fire environment. The pine tree thermal response numerical model is based on energy balance integral equations for the tree elements and mass balance integral equation for the water in the tree. The simulation performed considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The virtual three-dimensional tree model has a height of 7.5 m and is constituted by 8863 cylindrical elements representative of its trunks, branches and leaves. The fire front has 10 m long and a 2 m high. The study was conducted taking into account that the pine tree is located 5, 10 or 15 m from the fire front. For these three analyzed distances, the numerical results obtained regarding to the distribution of the view factors, mean radiant temperature and surface temperatures of the pine tree are presented. As main conclusion, it can be stated that the values of the view factor, MRT and surface temperatures of the pine tree decrease with increasing distance from the pine tree in front of fire.

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