Mathematical modelling of the spread of contamination during fires in forests exposed to radioactive contamination

The paper suggested in the context of the general mathematical model of forest fires [1] gives a new mathematical setting and method of numerical solution of a problem of a radioactive spread above the forest region. Numerical solution of problems of radioactive smoke spread during crown fire in exemplified heat energy release in the forest fire front was found. Heat energy release in the forest fire front was found to cause further radioactive particles spread by the action of wind. In the absence of wind, radioactive smoke particles deposit again on the underlying surface after a time. As a wind velocity increases, these particles are transferred in the ground layer over distances proportional to a wind velocity

Estimation of the influence of wood-fire retardants on fire behavior of some types of wood construction materials

In this paper the effect of fire front on the surface of wood samples (pine, aspen and larch) was presented to estimate the effect of different wood-fire retardants. Infrared thermography was used as a diagnostic method. Modern methods of IR-diagnostics and the use of thermal imagers eliminate the need for a large number of thermocouples, which perturb the investigated medium during measurements. At the same time, a much better resolution in space and time can be obtained using infrared diagnostics. The surface temperature distribution was obtained for the test wood samples after exposure to a fire front that was modeled using pine needles. The ignition probability was estimated for the chosen experimental parameters for each kind of wood. In the infrared region the sample surface characteristics were recorded using a thermal imager JADE J530SB with a 2.5–2.7 micron optical filter that allowed a temperature to be measured in the range of 500–850 K. In order to record a temperature in the range of 293–550 K, the recording was conducted without a filter. The fire hazard characteristics of wood after fire retardant treatment showed a significant reduction in the surface temperature and the resistance to fire for the chosen parameters of the experiment compared to the same untreated sample

NEM and MFEM Simulation of Interaction between Time-dependent Waves and Obstacles

Fundamental research challenge of structural integrity and construction resistance while interacting with fluid or gas is of high importance when estimating their efficiency and lifetime. The paper presents the simulation results of interaction between incompressible ideal fluid and an escarpment at the bottom, and interaction between viscous incompressible fluid and an obstacle above fluid surface. Flow patterns at different times and chronograms of hydrodynamic loads on solid walls of computational domain, horizontal and vertical obstacles are displayed

Simulation of impact assessment of crown forest fires on boundary layer of atmosphere using software PHOENICS

Mathematical model of heat and mass transfer of crown forest fire is used in this paper, which is developed on the base of experimental research data and laws and methods of mechanics of reacting media. The numerical calculation carried out using software PHOENICS for non stationary three dimensional case. K-ε model of turbulence is taken into account. It is studied the influence of temperature and wind velocity in boundary layer of atmosphere on the turbulent kinematic viscosity coefficient value and distribution of temperature above the crown forest fire front

Improvement of firebrand tracking and detection software

Burning and glowing firebrands generated by wildland and urban fires may lead to the initiation of spot fnes and the ignition of structures. One of the ways to obtain this infonnation is to process tliennal video files. Earlier, a number of algorithms were developed for the analysis of the characteristics of fu'ebrands under field conditions. However, they had certain disadvantages. In this regard, this work is devoted to the development of new algorithms and their testing

Mathematical modelling of the spread of contamination during fires in forests exposed to radioactive contamination

The paper suggested in the context of the general mathematical model of forest fires [1] gives a new mathematical setting and method of numerical solution of a problem of a radioactive spread above the forest region. Numerical solution of problems of radioactive smoke spread during crown fire in exemplified heat energy release in the forest fire front was found. Heat energy release in the forest fire front was found to cause further radioactive particles spread by the action of wind. In the absence of wind, radioactive smoke particles deposit again on the underlying surface after a time. As a wind velocity increases, these particles are transferred in the ground layer over distances proportional to a wind velocity

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

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