Abstract
In Mokkoku irrigation reservoir the siphon pipe is very long compared with the siphon pipe in usual reservoir and the diameter of siphon pipe is longer than that of usual reservoir. There were no data to estimate the volume of air release from the water in low pressure of such a large scale siphon pipe. The model siphon pipe was used to do experiment for estimating the air release and the volume of air release was estimated by experimental result. If the velocity of the water in the siphon pipe is high the released air is carried down by flowing water. Soitisnecessary to clear by the boundary of velocity when the air would be carried out by the velocity of water for design of air removal system in siphon pipe. Through the theoretical analysis of air removal in slope pipe the relation of slope and velocity to carry the air should be clearly known.
During the experiment four kinds of pipe diameter (45, 75, 100 and 200mm) were used. The boundary of velocity in slope pipe to move the air was cleared. The experiment of air release in low pressure was carried out by using 25, 50 and 75 mm pipe diameters. The characteristics of air release under low pressure were gained. Using the experimental results the capacity of air removal system in siphon pipe of Mokkoku reservoir was designed.
