Study of flows induced by injection of a hot gas in a mechanically ventilated room. Application to the study of smoke propagation from a fire in a confined environment ventilated from a source area to a target area
Caroline LUCCHESI, doctorate of Uiversity de la méditerranée - Aix-Marseille II, 210 p., defended on the 14th january 2009
The thesis deals with fire smoke propagation phenomena for typical nudear facility scenario: two rooms connected with an open door. The objective is to study propagation phenomena in the final goal of improving the knowledge for safety and proposing data base for code validation. The methodology is based on the combination of three experimental approaches: reduced scale isothermal approach using air/helium gas mixture, reduced scale thermal approach using combustion of smalt cup of hydrocarbon and large scale approach with fire tests. The study focuses on filling process in the "source" room, the flow at the doorway and the spHt plume in the target room. The filling process investigation shows the influence of enrolments on air entrainment and the effect of thermal losses on the stratification. A coarse description of the flow at the doorway is proposed. The behaviour of the spill plume points out two regimes of spilling, the trajectory characteristic and the location of the impact at the ceiling. Several tapies are investigated: the location af high temperature regions, the effect of mechanical ventilation, the effect of the dimension of the doorway, the trajectory of the spill plume, the effect of the convection heat flow. In addition, visualisations af smoke flow at large scale with laser techniques have been performed.