Experimental charaterisation of thermal plumes in confined ventilated spaces

This paper presents the behaviour of a thermal plume combine with a forced ventilation. A method to locate the position of the thermocline in a ventilated room is shown. It also gives and compares the results obtained by means of a solutal simulation on an hydraulic model and from full-scale experiments in a climatic chamber.

Passive control of a free jet

This paper deals with low Reynolds number jets for personalised ventilation and the possibility to control them in order to obtain useful modifications of the flow field, it can be done by simply adding a ring-like perturbation in front of the jet itself.

Flow behaviour in a ventilated room - Measurements and simulations -

Disturbances from the surroundind environment and boundary conditions can influence very much the flow pattern , particles concentration and temperature distribution in a room.This report confirms the importance of working with measurements and simulations in parallel. Simulations of indoor air quality need to be validated . Guidelines on how to combine results are discussed in the paper.

The impact of an uniformly distributed thermal load on mixed flow

Experiments were carried out in a scaled test room equipped with 9 vortex inlets uniformly distributed, exhaust outlets near the floor and 64 mannequins to simulate cooling loads. The study describes the air flow pattern observed and the relationship between the air velocity and the cooling load per m2 for mixed flow.

Experimental study on a ductless air supply system using low temperature air

Experioments has been conducted with a ice thermal storage and a ceiling plenum. This ductless air supply system can be an alternative to the use of chilled water tubes. This system supplies air to the ceiling plenum chamber by mixing return air and low temperature air.

Predicting volatile organic compounds concentration in residential buildings (Part 2 : application of model)

Using the model developed in part 1 of this paper, the influence of material kinds, ventilation and air-cleaning device on VOC concentration in room is studied. The conclusion is that ventilation rate plays a very important role on VOCs concentration, but it affects little on VOCs emission rate.

Modeling chemical reactions in the indoor environment by CFD

The study used CFD to examine reactions between ozone and terpenes in a room under 4 conditions. The study indicates that chemical reactions can significantly alter the concentration of air pollutants, an imperfect mixing may result in reactant and product concentrations significantly different from those predicted by the model that assumes fully mixed conditions.

Improved prediction of heat transfer in horizontal thermally unstably stratified boundary layers by resolution of the large-scale buoyant structures.

When using RANS turbulence models the mean profiles of mixed convection can be predicted with accuracy. It is more important to resolve large scale 3D structures instead of using very complex turbulence models, for the prediction of room airflow with floor heating or cooled ceiling.

Simulation tool for indoor air quality improvement in a covered swimming pool

This study consisted first in a sampling campaign that has shown the important levels of NCL3 encountered in swimming pools. Then a simulation of the NCL3 dispersion was conducted wtih the following simulation tools : TRNSYS (thermal simulation) and FLUENT (CFD simulation).

Lärmbekampfung in RLT-Anlagen, Teil 2 Noise reduction in ventilation systems, part 2

The methods for estimating or calculating the noise reduction in ductwork are described. Information is given about noise propagation in straight circular or rectangular ducts and in ducts with diameters changes, bends, elbows or junctions. Noise reduction by air diffusers, filters, coils, is also presented, as well as noise emission by ducts walls.

Pages