Abstract
The purpose of this study is to show the applicability of J-Groove for controlling swirl flow in a draft tube of water turbine. J-Groove is very simple device composed of shallow grooves mounted parallel to the pressure gradient on the diffuser wall. Experiment with J-Groove has been performed using the conical diffuser with the divergent angle of 20 degrees. The pressure fluctuation on the wall has been measured to show the effect of J-Groove for the spiral vortex core in the diffuser.
