modelling

Working spaces in modem buildings are easily formed by interior partitions because these buildings have been designed and constructed as open spaces for flexibility. This could lead to an indoor environment which might be different from the intended design. In this study, the effect of partition on the indoor air quality in a model room has been investigated with different configurations such as the height of' partition and the gap between partition and floor.

The general strategy adopted in the development of a computational tool performing the identification of parametric models based on the Residence Times Distribution (Rm) theory is exposed. Two main aspects of the modelling procedure are presented: the structural discrimination of the various solution schemes, and the parameters estimation step. The structural model determination is solved by a stochastic procedure based on a Simulated Annealing algorithm, while the parametric identification is solved by a nonlinear deterministic procedure.

There are many indices to evaluate the ventilation characteristics of the ventilated rooms. These indices are classified into air change efficiency and contaminant removal effectiveness. In order to know how to use many indjces for a good understanding of the characteristics of the concerned ventilation system, the values of various efficiencies under some typical air flow conditions with isothermal condition are compared. The local mean age distributions and local contaminant concentrations are measured with tracer gas technique in a scaled model of the room ventilated mechanically.

A Computational. Fluid Dynamics technique is employed to predict the two dimensional turbulent air flow which is created by an Aaberg slot exhaust hood reinforced by a two-dimensional wall jet flow. The standard turbulent k-e model, control volume method and SIMPLE algorithm are tised to simulate the air flow. The numerical results for the effect of the Aaberg slot exhaust hood on the air flow pattern, shape of the capture region and the velocity distribution of the capture region in the system are presented.

We examine transient displacement flows in naturally ventilated spaces that are subject to an increase in internal heat gains as in, for example, an empty lecture theatre which is then occupied by an audience. Heat gains create a layer of warm air at the ceiling which initially increases in depth and temperature, and descends towards the occupied regions. A theoretical model is developed to predict the time-dependent movement of the interface that separates the warm upper and cool lower layers of air, and comparisons are made with the results of laboratory experiments.

Forced air circulation in a storage room either with freezing/cooling or controlled atmosphere is usually turbulent because a high air change rate is generally required. The interaction between the turbulent air flow and the product layers plays an important role in the performance of the storage room. In this paper, a homogenous model based on the Brinkman-Forchheimer-extended Darcy equation for both fluid and porous layer is described, in association with the standard k-e turbulence model.

Predicting the movement of smoke in a naturally ventilated building is a difficult process for architects and design engineers alike. A software model developed by the Fire Research Station may provide a solution.

The aim of this study was to ascertain the validity of using computational fluid dynamics (CFD) techniques to predict the behaviour of three dimensional gravity induced natural convection buoyant plumes from a vertical heated cylinder in a large quiescent enclosure. The calculated velocity distributions and turbulence quantities over the cylinder were compared to a wide range of experimental measurements. The laminar boundary layer on an isothermal vertical plate was also modelled. The CFX4.

The paper presents the results of the research on application of the equation describing the increase in the air volume flux in buoyant plume above a point heat source to calculate plumes in rooms with displacement ventilation.The tests carried out in test room have given information about practical defining of the distance from the origin, assuming entrainment coefficient values and possibilities of assuming equal widths of temperature and velocity profiles in order to determine the origin distance.