Renewable Energy.
Renewable Energy.

The research article 'Numerical investigation on characteristics of transient process in centrifugal pumps during power failure' has been published in the journal  Renewable Energy.

Abstract

Centrifugal pumps are widely applied in engineering practices. Power failure occurs occasionally and consequently the flow field inside the pump is extremely complex. Pump parameters fluctuate greatly with time during power failure, and such fluctuations cause high pressure pulsations in the flow and vibrations in the pump system. In this work, the transient process caused by the power failure of a centrifugal pump is simulated using ANSYS CFX, along with a user-defined function developed to solve iteratively the angular momentum equation for calculating pump rotational speed. Experiments are conducted to obtain the external characteristics curves and pump runaway parameters. Results show that the characteristic curves and runaway parameters of the pump predicted by numerical simulations are in good agreement with experimental ones. After power failure, the transient process experiences mainly four modes, namely, pump mode, braking mode, turbine mode and runaway mode. The variations of pump characteristic parameters with time are examined in detail. Furthermore, internal flow fields during the transient process are analyzed and compared to improve the understanding of flow behavior after pump power failure.

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