1991 年 11 巻 Supplement1 号 p. 123-126
Studies of seeing conditions inside telescope domes indicate a need to provice substantial air ventilation to prevent image degradation due to thermal variation of the air within the dome that means fluid-dynamic designing is necessary for choosing dome style. Althoughthe traditional enclosure is a cylinder topped by a hemispherical dome, alternative style such as flat-loof or tapezoidal topped cylinder could be considered from view point of fluid dynamic feature. Significant flushing flow without thermal ground boundary layer coming into the dome is the subjects to investigate. Water channel tests were made using 3 Types of 1:500 scale enclosure models with flow visualization methods. Dye injection method was mainly used and some quantitative measurements were done. Among the models, the cylindrer with near-flat roofs appear to be superior. And the sidewalls on either side of the telescope were found to be beneficial for flushing the flow.