抄録
In the drip irrigation system, the variation in head along the lateral line changes emitter discharge along line. Because of this reason, usually, it is impossible to gain the same emitter discharge along the line. But in the drip irrigation system with microtubing, by the selection of length of microtubing in accordance with the head in lateral line, the same emitter discharge along the line is gained.
The friction factor in microtubing was examined experimentally. The result indicated that the friction factor is shown by 64/Re in laminar flow in which Re is Reynolds number. There are two flow pattern occurred at the tip of the microtubing. One is the drip flow and the other hand is the jet flow. The boundary of drip and jet flow in microtubing was clarified experimentally. If the jet flow is used, the soil errosion occurs, therefore we must keep the drip flow at the tip of microtubing.
The characteristics of the design method proposed in this paper are as follows.
1. The emitter discharge along the lateral line is same.
2. The drip flow occur at the tip of microtubing.
For the application in the field, the analysis example was shown.
