Air flow conditions at the supply opening, which are used as boundary conditions in a numerical simulation, must be applied in order to proceed with the numerical solution of the air flow within a room. Among the conditions usually specified are the turbulence parameters, including the turbulence kinetic energy or the turbulence intensity and turbulent kinetic energy dissipation rate. Investigators have used a variety of expressions to estimate these quantities. A review of these expressions is presented in this paper.

In modem livestock buildings air distribution and air quality are important parameters to animal welfare and to the health of full-time employees in animal production. Traditional methods for calculating air distribution in farm buildings are mainly based on formulas for air jets which do not include the effect of room geometry, obstacles or heat sources. This paper describes the use of Computational Fluid Dynamics to predict air flow patterns and temperature distribution in a ventilated space.

The work was concerned with measuring natural convection through a large horizontal opening between two rooms in a building. Airflow rates between the two rooms were measured using a tracer-gas decay technique. Room 1 was heated to various temperatures in the range l8°C to 33°C using thermostatically-controlled heaters. Room 2 was unheated. A multi-point sampling unit was used to collect tracer-gas samples from each room. The concentration of SF6 tracer was measured using an infra-red gas analyser.