Modelling of Plume Penetration through a Supply Air Jet

The accumulation of heat, contaminant and water vapour into the upper part of rooms is utilized in stratification and zoning room air conditioning strategies. For the zoning strategy the plume penetration through the supply air jet is an essential parameter in modelling the temperature, concentration and humidity in the lower and upper zones of the room. This paper presents an analytical method for modelling the plume penetration for an air distribution method based on horizontal inclined jets of industrial grilles. The model is based on the forces created by the supply air jet and buoyancy. The model was evaluated with test room experiments, which were carried out with two methods: helium-filled soap bubbles and visual inspection of smoke videos. The results showed the model to work moderately. The experiments showed that in many cases the phenomena of collision of two air flows was very unstable in the relatively small test room.