Abstract
The ventilation characteristics in large half-enclosed building spaces were investigated for spherical dome models, a cylindrical building model and a rectangular one using video digital image processing techniques. In the case of the spherical dome models, mean video image signal values in the domes were inversely proportional to the opening ratios of the movable roof. The height of separated flows above the movable roofs was found to be the largest in the case of the rectangular building model. The average time of video image signals showed that 25 seconds was seen to be long enough for the running average to stabilize.