Plumes in Confined Spaces

Imagine that we enclose the plume, as shown in Fig. 7.74. The plume still entrains air from the surroundings, but the available fresh air is limited. This means that fresh air will surround the plume only up to a certain level. Above this level, the entrained air has to be recirculated from the plume itself. This leads to a two-zone flow model, wirh a layer of fresh air at the borrorn, and warmer air from the plume at the top. The interface between the two layers is located at the height at which the entrained air in the plume equals the supplied air. rhis can be found from the volume-flow formulae of Section 7.5.2. 

We now put the hot cylinder of Example 7.5.3 inside a room. The convective heat output is still = 5 kW. The air is supplied at the floor, as shown in 

From Table 7.19 we find the air volume flow (, ) in the plume as a function of the height above the floor (z)  

Wc can rearrange the equation so that we find the height for a given air volume flow in the plume  

CHAPTER 7 PRINCIPLES OF AIR AND CONTAMINANT MOVEMENT INSIDE AND AROUND BUILDINGS 

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