On the natural displacement flow through a full-scale enclosure, and the importance of the radiative participation of the water vapour content of the ambient air

Experiments were operated to determine the thermal stratification in a full-scale enclosure with natural ventilation driven by thermal source. Results provided by various predictive techniques were compared with experimental data. The salt-bath modelling technique and related mathematical model of Linden appear to be unappropriate for this type of air flow. CFD gives realistic predictions, especially when using a complete thermal radiation model.

Theoretical and experimental investigation of impinging jet ventilation and comparison with wall displacement ventilation.

Experimental data for an impinging jet in a room are presented in this paper and non-dimensional expressions for the decay of maximum velocity over the floor are derived. The performance of that system is compared with the one of a wall displacement ventilation.

Efficient ventilation of VOC spread in a small-scale painting process

On account of Volatile Organic Compounds (VOCs), large proportions of workers suffer from eye and respiratory discomfort or headaches. In a small-scale painting process, efficient ventilation system must be provided for human health. In this study, ventilation characteristics of toluene have been analysed in a room of a small-scale painting process with various exit locations with different suction velocities at the exits.

Prediction of indoor gaseous pollutant dispersion by nesting sub-zones within a multizone model

A zonal model has been nested within a multizone model to allow increased resolution in the prediction of local air flow velocities, temperature and concentration distributions between and within rooms. Simulations from the new program have been compared with measurements and results from other models.

A simplified system for indoor airflow simulation

This paper presents a simplified system based on a new air supply opening model along with a numerical method to accelerate and simplify the convergence procedure of predicting air distribution in ventilated rooms. The new numerical method is called error pre-treatment method. It is simpler than multi-grid method and effective for SIMPLE algorithm commonly used for indoor airflow simulation.

Measurements of air temperatures close to a low-velocity diffuser in displacement ventilation using an infrared camera

The authors have developed a whole-field measuring technique that allows the visualization of air temperatures and airflow patterns over a large cross-section. For that measurement, an infrared camera and a measuring screen placed in the airflow are used. Thanks to that technique, real-time images within large areas can be recorded and transient events can be captured. The method was applied to a flow from a low-velocity diffuser in displacement ventilation.

Review of airflow measurements techniques

Airflow measurements techniques are necessary to determine the most basic of inddoor air quality questions : "Is there enough fresh air to provide a healthy environment for the occupants of the building?" . This publication outlines airflow measurement techniques, but it does not make recommendations for techniques that should be used. The airflows that are discussed are those within a room or zone, those between or zones, such as through doorways (open or closed) or passive vents, those between the building and outdoors, and those through mechanical air distribution systems.

A numerical investigation of effects of a moving operator on airflow patterns in a cleanroom

In this paper, the variations of the airflow induced by a moving operator in a cleanroom installed with a curtain, are studied numerically. The effects of the moving operator and curtain on the airflow patterns are taken into account.

Predicting the pressure coefficients in a naturally ventilated test room using artificial neural networks

In this paper, the objective of the authors is to investigate the use of artificial neural networks for the prediction of air pressure coefficients across the openings in a light weight single-sided naturally ventilated test room.

Comparing zonal and CFD model predictions of indoor airflows under mixed convection conditions to experimental data

The present work is part of a research effort aimed at integrating a detailed model of airflow in large spaces with an algebraic multizone infiltration model to describe pollutant transport and coupled air flows within and between complex buildings and large spaces. In the past 15 years, zonal models were developed with the goal to obtain an approximate prediction of airflow characteristics in large indoor spaces. Also, reducing the number of grids in CFD models is a natural way of decreasing their demand of computational resources to solve air flows in room.