The Outflow of Buoyant Releases Including Fire Gases From a Long Corridor Closed at One End

Abstract

A new simple model is presented for the outflow of buoyant releases, including fire gases, from a long corridor closed at one end. A physical description of the model and application to well-documented data justify and validate the present model. The analysis incorporates the interaction of gravity (buoyancy) forces, turbulence, and entrainment rates into the plume rising from the fire. The model provides equations for predicting the temperature rise and the velocity in the ceiling layer if one knows the heat release rate from the fire and the air entrainment into the fire plume before the plume is submerged in the ceiling layer. Limited data and analysis indicate that the present flow situation allows a maximum entrainment rate into the fire beyond which the rate of the flow entering the corridor at the open end cannot further increase, i.e., the flow is choked. Although the data analyzed in this paper could not include buoyant outflows produced by fires at the end of a long corridor, the present model can be extended to apply for such flows as it is suggested by a recent Japanese paper [6] and other similar flows [3]. Of course, more experiments using fires in corridors are desirable to validate the present model.