Fundamental atrium design for natural ventilation

This paper focuses on the degree of flow enhancement achieved by an atrium which is itself ventilated directly by a low-level connection to the exterior.A theoretical model is designed to predict the steady stack-driven displacement flow along with the thermal stratification in the building due to heat gains in the storey and solar gains in the atrium. Comparison is then made with the results of laboratory experiments

Air flow distribution in and around a single-sided naturally ventilated room

This paper aims at comparing calculated and measured air flow distributions inside a naturally ventilated test room. Wind tunnel trials were carried out in the test room.Separate air flow and thermal modelling programs are used to predict the spatial distribution of the air flow and thermal comfort.

Deterministic simulation and assessment of air-recirculation performance of unidirectional-flow cleanrooms that incorporate age of air concept.

A CFD model that incorporates fan-performance characteristics was applied to investigate and compare the air-recirculation performance of the two general designs of unidirectional-flow cleanrooms. For the simulation, typical flow-resistance models of the various components in the air path were used.

Airflow characteristics in the outlet region of a vortex room air diffuser

In this paper, the airflow characteristics in the outlet region of a generic vortex diffuser are experimentally and numerically investigated. A specific arrangement of tetrahedral and hexahedral cells was used in grid generation: it has been found ideal for the analysis of the room air movement due to an air diffuser.
Corresponding airflow measurements were conducted by using a three dimensional ultrasonic anemometer.

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.

Fault-tolerant control for outdoor ventilation air flow rate in buildings based on neural network

A supervisory control scheme for a sensor based demand-controlled ventilation system is described in this paper. The strategy based on neural network models is used to diagnose the measurement faults of outdoor and supply air flow sensors, and makes the fault-tolerant control of outdoor air flow when faults occur. Tests using that dynamic system simulation have been conducted to validate the strategy.

Automatically generated zonal models for building air flow simulation: principles and applications

Starting from models library, a zonal model of an entire building can be constructed by assembling the appropriate modules. A model-generating tool called GenSPARK makes the process automatic. This paper describes how that tool works and give examples of configurations that can be analyzed.

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.

Measurement and calculation of the neutral height in a room with displacement ventilation

Thanks to an environmental chamber equipped with a displacement ventilation system, neutral height measurements were carried out with the presence of a heated mannequin and other heat sources.The relationship between the neutral height for air distribution and the ventilation load in a room with displacement ventilation was investigated.

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.

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