2426 サイホン管内流れの遮断に関する研究(S41-4 流体機械に関連した複雑内部流動の解析と計測(トルクコンバータ・水車・ポンプ),S41 流体機械に関連した複雑内部流動の解析と計測)  [in Japanese] 2426 An Experimental Study on the Shut-off of Siphon Flow  [in Japanese]

In micro hydro-turbine systems, there are cases to adopt a siphon pipe for the penstock to reduce the construction cost. And it has the feature that the flow in the pipe is easy to stop at the load rejection of a hydro-turbine by using the natural air admission. However, few works have been made to investigate siphon phenomena. Thus, the present experimental study is aimed to make clear the effect of admitted air on the flow in a siphon-pipe. To clarify the transient phenomena from the beginning of air admission to the shut-off of the flow, water and air flow rates, wall pressure near the air port in a siphon-pipe (50mm in dia.) were measured. Flow visualization was also made to see the flow behavior, which was taken from outside by a CCD camera. Based on the dimensional consideration applied to the experimental data, correlation to specify the required time for shut-off has been made.