scholarly journals Thermal field of the southern taiga landscape of the Russian plain

2019 ◽  
pp. 51-68 ◽  
Author(s):  
Yu. G. Puzachenko ◽  
A. S. Baibar ◽  
A. V. Varlagin ◽  
R. B. Sandlersky ◽  
A. N. Krenke
Keyword(s):  
Heat Flux ◽  
Thermal Field ◽  
Direct Interaction ◽  
Southern Taiga ◽  
Order Parameters ◽  
Ground Layer ◽  
Russian Plain ◽  
Transition Zones ◽  
Wave Channel

The technology of allocation of order parameters (invariants) of the spatial structure of the thermal field of the southern taiga landscape (Central Forest Nature Reserve) obtained on the basis of the analysis of the time series of measurements in the long-wave channel of Landsat satellites from 1986 to 2017 and reflecting its stationary state is considered. It is shown that the heat flux is measured by the satellite not directly from the forest crowns, but from the ground layer of the atmosphere, the state of which is determined by the parameters of the landscape. It is found that the invariant component of the spatiotemporal variation of the thermal field is displayed by two order parameters: the first mainly reflects the temperature of winter months, the second – of summer. The contribution of relief and vegetation to the determination of invariants and the autochthonous components of the thermal field determined by the transition zones between the landscape elements contrasting in thermal radiation are revealed. It is shown that the thermal field measured by the satellite reflects the heat flux from the ground layer of the atmosphere, which is in direct interaction with the landscape cover.

Methodology of Estimation of Fire Separation Distances between Construction Facilities by Calculation

2020 ◽  
Vol 1006 ◽  
pp. 93-100
Author(s):  
Vadym Nizhnyk ◽  
Yurii Feshchuk ◽  
Volodymyr Borovykov
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Linear Regression ◽  
Ignition Temperature ◽  
Oil Products ◽  
Regression Equations ◽  
Fire Load ◽  
Literary Sources ◽  
Tabular Method

Based on analysis of appropriate literary sources we established that estimation of fire separation distances was based of two criteria: heat flux and temperature. We proposed to use “ignition temperature of materials” as principal criterion when determining fire separation distances between adjacent construction facilities. Based on the results derived while performing complete factorial we created mathematical model to describe trend of changing fire separation distances depending on caloric power of fire load (Q), openings factor of the external enclosing structures (k) and duration of irradiation (t); moreover, its adequacy was confirmed. Based on linear regression equations we substantiated calculation and tabular method for the determination of fire separation distances for a facility being irradiated which contains combustible or otherwise non-combustible façade and a facility where liquid oil products turn. We developed and proposed general methodology for estimation of fire separation distances between construction facilities by calculation.

scholarly journals SIMULATION TESTS OF EXTINGUISHING PROCESS USING MIST NOZZLES WITH APPLICATION OF HYBRID FIRE MODEL

2016 ◽  
Vol 22 (4) ◽  
pp. 573-583 ◽  
Author(s):  
Jerzy GAŁAJ ◽  
Marek KONECKI ◽  
Ritoldas ŠUKYS
Keyword(s):  
Heat Flux ◽  
Computer Model ◽  
Input Data ◽  
Elementary Cell ◽  
Characteristic Parameters ◽  
Computational Cell ◽  
Fire Model ◽  
Fire Extinguishing ◽  
Unique Approach

The article presents a computer model of the fire extinguishing process using mist nozzles. A previously developed hybrid fire model was used for this purpose. Assumptions and relationships were given to represent a math­ematical model of extinguishing process, which comprises a unique approach to the determination of sprinkling area in an elementary cell of field fire model. A description of simulation tests of the model was given for several different input data, differing by mean diameters of droplets. This enabled a study of their effects on such output parameters as received heat flux, temperature and rate of its growth. For one selected computational cell located on the axis of the nozzle at floor level having the coordinates [10, 10, 1], the obtained results were presented in the form of heat flux and temperature. To simplify the analysis, characteristic parameters of particular curves were listed in the table. Conclusions formulated on the basis of results obtained during tests were specified at the end of work. They confirmed the expected regularity assuming that the extinguishing process was more effective in the case of droplets of a smaller diameter and greater sprinkling intensity. This allows assessing the degree, to which these stream parameters affect the extinguishing effectiveness.

Determination of calibration function in thermal field flow fractionation under thermal field programming

2006 ◽  
Vol 29 (8) ◽  
pp. 1088-1101 ◽  
Author(s):  
Luisa Pasti ◽  
Edgar A. Ventosa ◽  
Ines Mingozzi ◽  
Francesco Dondi
Keyword(s):  
Thermal Field ◽  
Field Flow Fractionation ◽  
Calibration Function ◽  
Flow Fractionation

A Model for Droplet Vaporization for Use in Gasoline and HCCI Engine Applications

2004 ◽  
Vol 126 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Youngchul Ra ◽  
Rolf D. Feitz
Keyword(s):  
Heat Flux ◽  
Internal Heat ◽  
Droplet Surface ◽  
Fuel Vapor ◽  
Gas Mixture ◽  
Ambient Temperatures ◽  
Droplet Vaporization ◽  
Flux Model ◽  
Heat Flux Model

A model for unsteady droplet vaporization is presented that considers the droplet temperature range from flash-boiling conditions to normal evaporation. The theory of continuous thermodynamics was used to model the properties and compositions of multicomponent fuels such as gasoline. In order to model the change of evaporation rate from normal to boiling conditions more realistically, an unsteady internal heat flux model and a new model for the determination of the droplet surface temperature is proposed. An explicit form of the equation to determine the heat flux from the surrounding gas mixture to the droplet-gas interface was obtained from an approximate solution of the quasi-steady energy equation for the surrounding gas mixture, with the inter-diffusion of fuel vapor and the surrounding gas taken into account. The model was applied to calculate evaporation processes of droplets for various ambient temperatures and droplet temperatures.

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