2436 障害板挿入によるポンプインデューサの脈動キャビテーションの抑制(S48-1 キャビテーション流れ(1),S48 キャビテーション流れ)  [in Japanese] 2436 Suppression of Cavitaiton Surge of Pump Inducer by Inserting Obstacle Plate  [in Japanese]

The attachment of an inducer upstream of the main impeller is a powerful method to improve the cavitation performance. It is known, however, that the cavitation surge oscillation, which is focused in the present paper, occurs under operation condition of partial flow rate and low suction pressure. The attempts to suppress the cavitation surge were made by installing a ring-shaped obstacle plate just upstream of inducer. The ring-shaped inlet plates with various blockage rates were tested to examine the effect of blockage rates on the suppression of cavitation surge for two kinds of inducers having two blades with the solidity of 2.0 and the different blade angle of 14°and 8°at the blade tip. In the present paper, the changes of the onset region of cavitation surge are clarified and the mechanism of cavitation surge suppression is discussed with casing wall pressure distribution and inlet velocity distribution.