Transient Behavior of a Cavitating Centrifugal Pump at Rapid Change in Operating Condition. 3rd Report. Classifications of Transient Phenomena.

Experimental data in present authors' first and second reports on transient characteristics of cavitating centrifugal pump were rearranged to get a criteria for the occurrence of the fluctuations of pressure and flowrate at a variety of transient operations. Transient behaviors were classified to the increasing and decreasing suction flowrate cases at transient operations. One dimensional unsteady flow analysis was applied to the transient phenomena and the calculated critical conditions for the occurrence of the fluctuations agree qualitatively with measured ones. The criteria for the occurrence of the fluctuating pressure and flowrate was presented for the transient phenomena during sudden opening/closure of discharge valve as well as starting/stopping of pump, by using newly introduced unsteady parameter.