On the use of air curtains to control smoke spread in an enclosed fire

We present results of a series of experiments in which a planer vertical turbulent jet (model air curtain) was used to confine the outflow from a round turbulent plume (model fire). Salt bath experiments using the light attenuation technique were used to measure the stratification that formed either side of the planar jet. The tests were configured such that the jet and plume both flowed in the same direction. When the plume was first started it flowed to the base of the tank and formed an outflow which slowly filled the region of the tank on the plume side of the planar jet with a dense salty layer. Some of this dense layer was entrained into the planar jet and was transferred to the other section of the enclosure. The developing stratification on the plume side of the jet eventually pushed the jet over and a large scale transfer of salty water across the jet ensued. A model is presented that uses a simplified filling box theory and a modified air curtain deflection modulus to predict the time at which the jet no longer constrains the stratification.