Strongly buoyant plume similarity and ‘small-fire’ ventilation
✍ Scribed by G.G. Rooney; P.F. Linden
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 1024 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0379-7112
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✦ Synopsis
We re-examine the problem of natural ventilation of a room containing afire, in the light of recent results obtained by Rooney and Linden (1996) concern-in9 the similarity solution for non-Boussinesq plumes. We consider the case of a steadyfire in a compartment with openings atfloor and ceiling levels, and obtain expressions for the depth and density of the homogeneous ceiling layer maintained by the fire plume. Taking the limit of a large lower opening area, we compare our results with experiments performed by Thomas et al. (1963). We also perform a sample calculation to estimate the size of the difference between the weakly and strongly buoyant cases. © 1998 Elsevier Science Ltd.
NOTATION
A 'Effective area' in Boussinesq ventilation model, see eqn (24) ,4 'Effective area' in non-Boussinesq ventilation model, see eqn (28) A I Area of floor covered by base of fire a Area of vent B Plume buoyancy flux b Plume radius c r Specific heat capacity at constant pressure D Diameter of fire source d Upper-layer depth F Scaled density deficit, a conserved quantity with units of buoyancy flux, see eqn (15) 9 Gravitational acceleration 9' Reduced gravity