English

The calculation of the infrared absorption in humid air (Schenker et al. 1995) has suggested an influence on the temperature and velocity profiles of the natural convection boundary layer. The profiles have been measured and confirm a small effect on the profiles in the laminar region of the flow but a strong one on the transition from laminar to turbulent flow. In a first approach based on the analytical solution for the conduction regime expressions could be deduced showing at least qualitatively the same modification of the temperature and the velocity profiles as measured.

The purpose of the presented investigation is the comparison between measured data of the laminar and turbulent mixed convection and their approximation by wall functions. New wall functions were implemented in a FVM-research-code using unstructured grids, which was developed by the author. Numerical results are compared with a turbulent closed cavity flow.

In order to assess ventilation systems, ventilation and thermal comfort parameters are calculated. Parameters are temperature and ventilation efficiency and PMV I PPD. Two ventilation configurations are set: the supply grille is under the ceiling and tests are performed for 2 exhaust positions. Both are opposite the ceiling: the first one is under the ceiling and the second one is on the floor. In regards with extract position, the ventilation system is better when extract is on the floor. It appears that the air renewal does not influence neither ventilation nor temperature efficiency.

This paper presents an original air conditioning concept and design development elaborated for a large arena, designed to accommodate the indoor sporting events during the 2000 Olympic Games in Sydney, Australia. An air conditioning system, which provides a great level of flexibility and economical operation, has been developed and its performance studied in detail by the use of our computational fluid dynamics (CFD) software.

Usually, the performance of fan-coils is defined and measured in the laboratories only through thermal quantities. However, comfort conditions within a room depend also on the air flow pattern determined by the appliance. Therefore, an experimental procedure to evaluate the fluid dynamic performance of fan-coils has been developed.