NUMERICAL CALCULATION OF REVERSE STARTUP OF A SMALL RADIAL VANE PUMP.

In order to grasp the reverse startup characteristics of a small radial vane pump in the case of misoperation, a circulation piping system that includes the pump is established. Numerical simulation of the full three-dimensional unsteady incompressible viscous flow is performed based on the slip-grid technique and user-defined functions (UDF). According to the results, the static pressure fluctuation is small at the inlet of the centrifugal pump during the reverse startup, which differs significantly from the forward startup. Compared to the impeller rotational speed, the time required for the shaft power, head and flow curves to reach stability is lagged, with the largest lag being shaft power, followed by head and the smallest flow rate. During the startup, the region where the turbulent kinetic energy mainly occurs changes from the outlet of the volute to the flow path of the impeller. There is no turbulent dissipation rate near the leading edge of the blade; In the early stage of the reverse startup, the similar laws of centrifugal pumps are obviously not applicable. In the later stages of the startup, the similitude law can be basically applied to the performance prediction of centrifugal pumps. [ABSTRACT FROM AUTHOR]