Programme pour le thème C9 mercredi après midi salle M

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15H40 : n° 1386 Physical phenomena governing the behaviour of wildfires : numerical simulation of crown fires in boreal fores

Dominique Morvan Konstantin Gavrilov Dmitry Lyubimov
Laboratoire M2P2
This paper presents the physical phenomena contributing to the behaviour of wildfires. The problem was formulated using a multiphase approach, including the set of balance equations governing the coupled system formed by the vegetation and the surrounding atmosphere in the vicinity of the fire front. Some numerical simulations carried out for a crown fire in boreal forest are compared to data collected during an experimental campaign conducted in the North West territories in Canada.

16H00 : n° 1387 Assessment of the plume theory predictions of crown scorch using transport models

Jean-Luc Dupuy Vladimir Konovalov François Pimont Dominique Morvan Rod Linn
INRA
The aim of our work is to study numerically crown scorch as the effects of a fire line spreading through surface fuel under a tree canopy. The objective was to assess the usual assumptions made when one uses the Van Wagner criteria, which are indeed simple predictive models for crown scorch height, to estimate crown scorch. For this purpose the FIRESTAR 2D and FIRETEC wildfire simulators are used. We simulated the fire line by a heat source at ground level and mainly investigated the temperature field. As a first step, we ran computations of thermal plumes with no-wind and with no canopy, for first comparison to plume theory. The influence of crown existence on the temperature field above the heat source, as well as on crown scorch, was then investigated. As a second step, the effect of a wind to the plume, as well as to crown scorch, was shown for the no-canopy and canopy cases.

16H20 : n° 1398 Simulation of quasi-static and dynamic deformation processes in the zones of volcanic activity

Valeriy Pavlovich Matveenko Varvara Bogoyavlenskaya N.A. Trufanov I.N. Shardakov
Institute of Continuous Media Mechanics, UB RAS
The paper investigates the quasi-static and dynamic deformation processes in the zones of volcanic activity using for this purpose the methods of mathematical simulation. The mathematical formulation of the problem is based on the principle of virtual displacements, and numerical realization of the variational equation is based on the finite-element method. The possibilities of pressure recording in the magma chamber by means of measuring deformations at the outer Earth’s crust have been found. The vibrogram relationships have been obtained to identify the points of possible sensor location.