By means of a case study involving a severe case of coupled heat and sir flow in buildings, this paper aims to quantify the differences resulting from different methods (ping-pong and onion approach) for linking heat and air flow models. The main conclusion is that when used improperly, the onion method will have implications in terms of computing resources, but - more seriously - the ping-pong method may generate substantial errors.
In order that sampling points may be strategically located, it is desirable to have knowledge of the spatial variation of ventilation eflectiveness parameters prior to measuring them using tracer gas sampling techniques. The research described in this paper is being carried out to establish a tracer gas sampling strategy as well as to facilitate the prediction of ventilation effectiveness parameters. The procedure developed requires the division of the internal space into a large number of cells and, by the application of CFD, the mass flow rates between adjacent cells to be established.
The IEA Annex 27, "Evaluation and Demonstration of Domestic Ventilation Systems" is aiming at developing tools by using the most developed computer models and equations available including modul development. Before staring up all the simulations an in depth review of the variables influencing the evaluation of a ventilation system have been done and a report is to be published. All parameters are needed to be mapped so that realistic assumptions can be made for the simulation phase.
A new multizone airflow and contaminant dispersal program CONTAM93 is described. While this program is based on existing theory of network airflow analysis and contaminant dispersal, it employs a unique graphic interface for data input and display. The interface uses a sketchpad to describe the connections between zones and icons to represent zones, openings, ventilation system components, and contaminant sources and sinks. The program, its graphic interface and plans for its further development are described.
Login