Study on three-dimensional characteristics of natural ventilation in half-enclosed buildings using video imaging techniques

Abstract

Video imaging techniques were used to examine visualized contaminant air flows in two types of half-enclosed buildings. Two-dimensional images of concentration in the half-enclosed building spaces were analyzed by an Image Processor and were then combined into three-dimensional images using the graphic software library of a SGI IRIS workstation. The characteristics of natural ventilation induced by wind was investigated in detail. For the experiments examining the contaminant air flow in a high-rise residential building model, the three-dimensional images enabled a better understanding of ventilation characteristics of the court space within the building. For the domed building model, the images indicate that the air change rate was 7 times an hour when the reference velocity was 3 m/s and the removable roof opening ratio was 75%.