2516 ダリウス水車の適用落差範囲の拡大について(S47-2 自然の流体エネルギー利用技術(水車),S47 自然の流体エネルギー利用技術)  [in Japanese] 2516 On Extension of Applicable Head Range of Darrieus Turbine  [in Japanese]

Alternative values of parameters of Darrieus turbine on geometry and operating condition were studied based on experimental data in order to extend its applicable head range to higher one. The result shows that increase of blade number more than three, the optimum value, affects the most to increase the applicable head limit up to 1.5m in combination with a parallel-wall casing, head which is a lower limit by use of open-flume turbine. Operation at a higher rotating speed can also increase a cavitation margin for a given gross head, being expected to cope with temporary swollenness and to reduce maintenance cost in a long term operation. Adoption of a thick blade results in a decreased output power due to its inferior runner efficiency in spite of a merit of less pressure drop on blade surface and an improved upper limit of head.