Combined Natural Convection and Forced Flow Through Small Openings in a Horizontal Partition, With Special Reference to Flows in Multicompartment Enclosures

Estimates of the magnitude of buoyancy-driven exchange flows through openings in partitions that separate compartments are needed to assess the movement of toxic gases and smoke through buildings. An experiment using water and brine as a substitute for a light gas moving in a dense gas was designed to measure combined forced and buoyancy-driven exchange flow through a single opening in a horizontal partition. No theoretical treatment exists for this configuration. The same apparatus was used to determine the magnitude of the forced flow required to purge the opening of the oppositely directed buoyant component (i.e., the “flooding” limit). Finally, combined forced and buoyancy-driven flows in a multicompartment enclosure were measured. It has been demonstrated that the combined forced and buoyancy-generated flows in the multicompartment structure can be predicted by a direct application of the results of the study of exchange flow through a single opening.