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Oscillating behaviors of fire-induced exchange flow through a horizontal ceiling vent in a compartment were studied in this paper. Experiments were conducted in a ceiling vent compartment with inner dimensions of 180.0 cm(L) × 120.0 cm(W) × 120.0 cm(H). A single vent configuration in the middle of the compartment ceiling was used. Various patterns of flow were shown by using the principle of smoke particles of laser scattering. The ratio of cross section of outflow and ceiling vent area and the oscillation frequency of outflow will then be obtained by image processing technology. Useful experimental results on these flow characteristics are derived which can be used for mass flow rate model establishment.

This paper describes a newly developed hybrid model to enable the simulation of smoke and heat movement in multicompartment buildings due to a fire. The hybrid model comprised two integrated models: a zone and a network model. The two-zone model was developed to simulate fire and smoke movement inside the room of fire-origin and neighboring compartments. The network model capable of predicting both mass and energy flow is used to simulate smoke movement into the rest of the compartments that are far away from the fire-origin room. The two models were combined to produce a hybrid model that allows an accurate simulation offire dynamics in both the near- and far-field. The paper illustrates the different steps of the development of the model. In a subsequent paper, the implementation of the developed hybrid model for different buildings will be discussed. In order to understand mass and heat transfer between compartments, two types of vent flows are discussed here: horizontal flow through a vertical vent, and vertical flow through a horizontal ceiling vent. Equations for both types of vent flows are presented in the paper. © 2011 ASHRAE., 2011 ASHRAE Winter Conference, 29 January 2011 through 2 February 2011, Las Vegas, NV