The work was concerned with measuring natural convection through a large horizontal opening of different sizes and shapes located 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 18°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.
The monitoring of the performance of domestic ventilation systems is quite a complex exercise. A wide variety of parameters must be taken into account in order that a suitable assessment of performance may be made - in many cases, insufficient data is collected. Even when the data has been collected, it is often the case that comparison of results from different studies is made very difficult due to variations in the treatment and presentation of the data.
As proposed in IEA Annex 20, a two dimensional case, for which detailed experimental data are available, has been specified by Nielsen to test different CFD codes. This report presents the results computed by the FLUENT code and he comparison between the computed results of thisreport and Chen and between measured results presented by Nielsen.
This report presents the computational results for the two-dimensional benchmark test case described in research item 1.45. The code used is EXACT3, standing for explicit time marching algorithm for continuous thermal fluid flow. It is a three-dimensional finite difference code for simulating buoyant turbulent airflows within buildings.