@inproceedings{oai:ynu.repo.nii.ac.jp:00003771,
 author = {Kurokawa, Junichi and Matsumoto, Kazunari and Matsui, Jun and Kitahora, Takaya},
 book = {Hydraulic machinery and cavitation : proceedings of the XIX IAHR Symposium : section on Hydraulic Machinery and Cavitation 9-11 September 1998, Singapore},
 month = {},
 note = {application/pdf, Pump efficiency drops rapidly with a decrease in specific speed Ns in the very low Ns range. In order to improve a pump efficiency and to establish the optimum design method of a very low specific speed pump in the range of Ns<100 [rpm,m3/min, m], eight kinds of centrifugal impellers were tested in the same volute casing designed at Ns -60. Three impellers have the same outlet angle of β2=22.5° with a different Ns ranging from 80 to 200, and the other five have radial vanes(β2=90°) from Ns=50 to 80.The results showed that the conventional design is not suitable for a very low Ns Pump and that the maximum efficiency is largely influenced by the volute design parameters, such as a volute tongue, a olute width and a gap between a impeller exit and a volute tongue, while the maximum efficiency differs little by the design of impeller. The BEP of a very low Ns pump agrees with the designed discharge of a volute and is far from that of an impeller.},
 publisher = {International Association of Hydraulic Research (IAHR)},
 title = {Performances of centrifugal pumps of very low specific speed},
 volume = {2},
 year = {1999}
}