らせん渦心を伴う吸出し管水圧脈動の診断法

概要

論文の詳細を見る
Since the operating range of a Francis turbine is limited by the draft tube surge, the magnitude of pressure fluctuation at the draft tube wall should be examined at the test using a model turbine. However, there is the serious problem that the nature of pressure fluctuation depends on the measuring point which differs point by point even in one cross section of the inlet cone. The present authors attempted to explain it as a result of the difference in phase between two fluctuating components, rotating type and synchronous type, both of which were generated by the orbital motion of a spiral vortex core. Thus, based on this concept, we developed a method to evaluate the two components separately using pressure data measured at two taps which were installed at an angle of 90 deg in the cross section. The experimental results indicate that the proposed method is usable as a diagnosis of pressure fluctuations which are generated by a spiral vortex core in a draft tube.
社団法人日本機械学会の論文
1989-08-25