Most indoor airflows are mixed convection. In order to simulate mixed convection accurately and efficiently, this paper uses a two-layer turbulence model. The two-layer model combines a one-equation model for near wall flow together with the standard k-E model for outer-wall flow. The model has been used to predict the mixed convection by displacement ventilation in an office. The computed results agree well with the corresponding airflow pattern and the distributions of air temperature , air velocity, air velocity fluctuation, and tracer-gas concentration.
The present paper deals with one of the most important mechanisms of inter-zone mass and energy transfer, namely the buoyancy-driven flows through stairwells that connect the floors of buildings. To further investigate these phenomena, experimental as well as theoretical studies have been carried out. A series of experiments have been performed in order to study the airflow through a typical stairwell that connects the two individual zones of a two-storey house. Airflow rates between the two zones were measured using a single tracer gas decay technique.
To evaluate the performance of different turbulence models in room airflow applications measurements in a test room will be compared to numerical calculations. The measurements are taken in a 6 x 4 x 3 m3 room with two heated dummies and a computer. Zero heat flux boundary conditions are achieved by controlling the inner and outer wall temperature. Two different ventilation systems will be examined in order to get momentum and buoyancy driven flow fields. Temperature measurement and Particle Streak Tracking data will be compared to the numerical predictions.
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