This paper reports experiments carried out in a scale model, about possibilities to use buoyancy forces to distribute air and heat through horizontal openings. Water and saline water have been used as operating fluids. This study focuses on the effect of a staircase on the fluid exchange through the horizontal opening. This research is planned to be carried on in a full scale 2 storey-building.
Two methods have been used for measurement of natural convection flows in a narrow vertical channel of which one wall is heated : a hot wire anemometer adapted to measurements in flows where temperature gradients exist (two hot wires with different overheat) and a method for attaining bulk flow information in boundary layer flows. Results from these two methods are compared.
This paper describes the CFD model implemented within a building simulation program (ESP-r). It gives results examples to demonstrate the application potential of the model to calculate local comfort conditions and air quality.
This paper deals with two general approaches used to determine multizone air flow by tracer gas experiments : a tracer gas decay model and a simultaneous release of n different tracer gases in n zones (n x n approach) . The results show a suitable agreement between the model and measurements made, at work-time, in a 3-store building equipped with an hybrid ventilation system.
The study was carried out on 6 subjects. Each one is seated at a desk with a mounted PVS. During the experiment the room air temperature was controlled at 28C and the personalized air temperature was 25C. Several fluctuations were tested, air movement with a frequency of 0.2 Hz was preferred to 0.1 Hz and 0.3 HZThe subjects had a preference for a lower mean air velocity but were more distracted when air movement fluctuated (0,2 Hz) than when it was constant.
In the paper, based on MS Thesis by Julinek, 2001, the authors describe CFD modelling of the natural and mixed convection of air inside the entrance atrium of the Moravian library in Brno, Czech Republic. The eight-floor high atrium is formed with eight galleries, which are linked together with staircase, on one side and with glass wall on the other side. Inside the atrium, combination of natural and forced ventilation is used.
Computed tomography consists in measuring chemical concentrations profiles in a room from the attenuation of a large number of laser rays and converting measurements in a two dimensional concentration profile by a reconstruction algorithm. This study shows the effectiveness of one of these algorithms (Low Third Derivative).
For that study , an heated manikin, in a seated position, is exposed to a local thermo ventilator that promotes a non-uniform horizontal flow ( front , behind and right side) ; an interior climate analyser measures the environmental variables around the manikin. Those data are used as inputs of the numerical program.
A numerical model simulates the human and clothing thermal systems and evaluates the thermal comfort level. Verification was made that when the ventilator is places in front of the manikin, acceptable thermal comfort conditions are fullfilled.
By means of CFD, the results of that study express a significant influence of Computer Simulated Person geometry on local flow pattern and on personal exposure to contaminants released from the floor surface.
The velocity field in circular ducts has been measured downstream 8 representative disturbances (elbows, junctions, damper, ...). The uncertainty in flow rate calculation has been defined.
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