Enclosure Smoke Filling and Management with Mechanical Ventilation

Enclosure smoke filling and management are addressed from the standpoint of the volumetric flow rates commonly used for mechanical ventilation system design. In this context, fire-induced gas expansion is treated as a volumetric source term. A two-layer analysis developed previously for enclosure smoke filling without mechanical ventilation is extended to consider the impact of mechanical ventilation on smoke layer descent rates and conditions within the smoke layer. A spreadsheet-based model of enclosure smoke filling developed in conjunction with the previous unventilated analysis is also extended to consider both mechanical extraction and injection systems. Some implications of mechanical ventilation on the development and descent of a smoke layer in an enclosure fire are discussed.