Fire Induced Flows Through Room Openings - Flow Coefficients

摘要

A full-scale experimental and theoretical study was made of steady-state fire-induced flows through doorway and window openings. Measurements included two-dimensional temperature and pressure-difference profiles within the opening and vertical temperature profiles within the rooms connected by the openings. A floor-level gas burner served as the energy source. Mass flow rates through the openings were calculated from the opening data. A static-pressure flow model was used to establish ideal orifice flows from different combinations of the experimental temperature profiles. The opening and ideal flow results were combined to form room-opening flow coefficients as a function of fire energy release rate, opening geometry, and fire location. Two calculation procedures were used to compute the ideal flow. An irrotational jet model for the flow coefficients was developed and found to be in reasonable agreement with these and other measurements. Measured flow coefficient results show no significant dependence on fire strength, opening geometry, or fire location, as long as the ideal mass flow rate was based on measured gas temperatures. However, the theory indicates a significant variation in flow coefficient with opening widths larger than those used in the experiments.