Abstract: The purpose of this study is to examine the validity of J-grooves in controlling and suppressing the swirl flow in a conical diffuser, for draft surge suppression in a Francis turbine, which ...

Abstract: In very low specific speed range (ns<0.25), the efficiency of the centrifugal pump designed by the conventional method becomes remarkably low. Therefore, positive-displacement pumps have been ...

Abstract: Cavitation is a serious problem in the development of high-speed turbopumps, and an inducer is often used to avoid cavitation in the main impeller. Thus, the inducer often operates under the ...

Abstract: The suppression of cavitation instabilities was attempted through the control of tip leakage vortex cavitation. The control was made by using shallow grooves, called J groove, on the casing ...

Abstract: In order to control and suppress rotating stall in the diffuser of a centrifugal turbomachine, a passive method of utilizing radial shallow grooves is proposed and its effect is studied ...

Abstract: In order to control and suppress instabilities caused by swirl flow, the authors have proposed a very simple passive method utilizing shallow grooves mounted on a casing wall or diffuser wall(s) ...

Abstract: In order to control and suppress performance curve instability characterized by the positive slope of head-capacity curve of a mixed flow pump, a very simple passive method utilizing shallow ...