@article{oai:ynu.repo.nii.ac.jp:00003774,
 author = {今村, 博 and 黒川, 淳一 and 松井, 純 and 高村, 修},
 issue = {676},
 journal = {日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B},
 month = {Dec},
 note = {application/pdf, The purpose of the study is to examine the validity of J-groove in controlling and suppressing swirl flow in conical diffuser, for draft surge suppression in a Francis turbine which is caused by the swirling flow from runner outlet into a draft tube. "J-groove" composed of shallow grooves mounted parallel to the pressure gradient on the diffuser wall is a very simple passive device to suppress several anomalous phenomena in turbomachinery. The experimental study has been performed using conical diffuser of divergent angle 20 degree. The measured results of velocity distribution in the diffuser show that considerable reduction of swirl intensity is attained by use of J-grooves. Besides, the amplitude of pressure fluctuation caused by rotation of vortex core around the dead water region near the diffuser inlet is reduced by J-grooves.},
 pages = {3325--3331},
 title = {Jグルーブによる広がり管内旋回流の抑制},
 volume = {68},
 year = {2002}
}