Analysis and prediction techniques.


Numerical simulation of indoor environment in large indoor spaces with natural ventilation. Part I: Development of a simultaneous simulation technique for inside and outside airflow of large indoor stadiums.

A purpose of this research work is to study the environmental control in large indoor stadiums which utilize the natural ventilation. In these problems, effects by the airflow in and around the stadium should be analyzed. In this research work, a numerical analysis technique which enables simultaneous simulation of indoor airflow and the airflow around buildings was developed adopting composite grid coordinate calculation technique. In this paper, an outline of this technique is described.

The strategic implications for large, dynamically insulated buildings in cities.

The concept of dynamic insulation, where cold air is drawn through porous insulation in a building envelope from outside to inside, thereby returning heat energy normally lost by conduction back into the interior of the building, has been studied by several researchers, in Japan, Europe and Canada. However the work to date has largely concentrated on the physical processes in individual wall, floor or roof elements and only a small number of experimental buildings (all of a small domestic scale) have been adequately monitored.

Sound attenuation in long enclosures.

An intensive review indicates that among the existing formulae on the sound attenuation in long enclosures, only the geometrical reflection model seems relatively practical. Computations with this model show the following for rectangular long enclosures: with a larger cross-sectional size the relative attenuation from a given section is less but the absolute attenuation with reference to the source power is greater; the efficiency of absorbers is higher when there is less absorption; and obtain a higher attenuation, the absorbers should be evenly arranged in a section.

Studies on the "ventilation effectiveness" and modification of the ventilation system in the waiting hall of a railway station.

The concept of ventilation effectiveness for mechanical ventilation of an airspace is reviewed and associated parameters for describing the performance of ventilation systems are described. The idea is applied to a study of the thermal environment in the waiting hall of a railway station. Two ventilation schemes: one with a ventilation system only and the other with an air-conditioning system were considered. The proposed air-conditioning system would provide air at a temperature only 5 °C below the ambient but with a higher air circulation rate.

Measurement of thermal stratification in large single-cell buildings.

This paper describes measured temperature profiles and thermal stratification in eight aircraft hangar buildings during the heating season. Presented also is the predicted impact of thermal stratification on heating energy requirements. The hangar buildings included two main ceiling heights (9.35 and 17.1 m (31 and 56 ft)), two ceiling types (fiat and Quonset), two types of heating systems (vertical discharge forced warm air and downdraft convective unit heaters), and various types of large external doors.