Due to the renewal of interest for solar chimneys (that convert thermal energy into the kinetic energy of air movement) , experiments were carried out in a controlled environment, with a full-scale chimney, where both air-velocity and air-temperature were measured.
The aim of the project was to get a better knowledge of :
- optimal gap to height ratio
- optimal gap to different heat input ratio
- optimal inclination angle
- methods to estimate the flow rate.

This paper sums up the developments in geophysical fluid dynamics and ocean currents related to dynamical phenomena. Examples from study of ocean flows are given, then several methods for studying nonlinear dynamical phenomena proposed. Those dynamical phenomena can be very significant for smoke control in naturally and hybrid ventilated buildings.

Experimental set-up and measurement procedures were carried out to evaluate the performance of a windcatcher, using an open working section wind tunnel. Then CFD simulations were made to be compared with experimental results.The performance of the windcatcher depends on the wind speed. The wind direction also has importance

In this paper, after theoretical considerations, two ventilation openings are analysed : an opening with top-hinged flap and a wall inlet with central flap. The analysis shows that it is possible to split artificial resistance coefficients from literature into pure resistance and pure contraction coefficients .

This paper is built on the hypothesis that, as the heated area increases from a point source, a displacement flow is maintained until the heated area reaches a critical fraction of the floor area, after which there is a transition to mixing flow.This hypothesis is tested in a series of laboratory experiments with the investigation of thermal stratification and flow patterns produced by a range of area heat sources located on the floor of a naturally ventilated enclosure.

This paper develops a simple analytical model for the air flow inside a room with different discrete heating and cooling sources, established by combined localised and distributed heat input. Results from experiments are compared to simple theoretical models of the flow pattern.

In this paper, cross ventilation is evaluated by the multi zone network airflow simulation and using CFD. The distribution of indoor wind velocity by cross ventilation is influenced by the weather condition, the location of the building and the form of he building. This paper takes into account those three indexes and proposes a new evaluation method of natural cross ventilation performance

Investigation by means of CFD and small-scale laboratory experiments showed that flow bifurcations could occur in building spaces ventilated by buoyancy force with large opening ceiling.A theoretical model has been developed to determine the ceiling opening size at which the flow bifurcation occurs.The predictions were in good agreement with the experimental results obtained in this work.

The wind tunnel experiment is the major method for cross ventilation researches. Up to now no quantitative evaluation method nor standard has been produced. This research project is to develop the quantitative method to predict cross ventilation rate driven by wind. A specially designed wind tunnel is used in the project. Conventional wind tunnel experiment is carried out in parallel with scale models of building without openings.

CFD and fluid net models used for natural ventilation designs do not consider the impacts of fluctuating characteristics to the mean airflow rate. This paper presents first a correctional method for predicting mean airflow rate of natural ventilation when the average wind velocity is more important than velocity fluctuation. A correctional coefficient for airflow resistance of multi-zone models is deduced. This method is then applied to a big atrium of a naturally ventilated five floor laboratory.