抄録
In the previous paper, the pressure Loss coefficient of branching rapidly increased when the flow ratio in a cross pipe was in a certain zone. In this experiment, the author observed the flow condition in a cross pipe by using a hydrogen bubble method. As a result of this experiment, it is made clear that the condition of the pressure loss is closely related to the formative mechanism of a vortex and setting a straightening vane in a grade crossing section of a cross pipe restrains the rapid increase of the pressure loss. This paper reports about these phenomena.
