Numerical Simulation of the Transient Flow in a Centrifugal Pump During Starting Period

Abstract

Computational fluid dynamics were used to study the three-dimensional unsteady incompressible viscous flows in a centrifugal pump during rapid starting period (≈0.12 s). The rotational speed variation of the field around the impeller was realized by a dynamic slip region method, which combines the dynamic mesh method with nonconformal grid boundaries. In order to avoid introducing errors brought by the externally specified unsteady inlet and outlet boundary conditions, a physical model composed of a pipe system and pump was developed for numerical self-coupling computation. The proposed method makes the computation processes more close to the real conditions. Relations between the instantaneous flow evolutions and the corresponding transient flow-rate, head, efficiency and power were analyzed. Relative velocity comparisons between the transient and the corresponding quasisteady results were discussed. Observations of the formations and evolutions of the primary vortices filled between the startup blades illustrate the features of the transient internal flow. The computational transient performances qualitatively agree with published data, indicating that the present method is capable of solving unsteady flow in a centrifugal pump under transient operations.

Numerical Simulation of the Transient Process of Power Failure in a Mixed Pump

“…CFD technology had been successfully used in the transient calculation of pumps during starting and stopping periods [6][7][8][9]. With this method, not only the external characteristic but also the internal flow field could be obtained clearly.…”

“…DM method has been successfully used in transient simulation of a 2-dimensional centrifugal pump during starting period [11]. Then Li et al [7] pushed on a further application of DM method in a 3-D centrifugal pump to simulate the transient characteristic during starting period. Liu et al [6] used DM method to simulate the stopping transient process.…”

Investigation of hydraulic force of a 1000-MW pressurized water reactor under hypothetical drop accident of core barrel assembly

“…All of these studies were focused mainly on the direct influence of flow-induced vibration on internal structures; while relatively little attention has been given to indirect effects such as the impact of internal structures on the pressurized water reactor (PWR). The dynamic mesh model can be applied to determine the dynamic properties of the internal structures, as evidenced by several previous studies-many prior researchers have utilized this technique to simulate the dynamic properties of various types of fluid machineries such as valves, [11][12][13][14][15][16][17] pumps, 18,19 and more. These previous works suggest that the dynamic mesh model is well suited to analysis of a hypothetical drop accident in a PWR.…”

Dynamic Simulation in Guide Vane Opening Process of a Pump-Turbine in Pump Mode

“…Experiments conducted by (Thanapandi and Prasad 1995) showed that pump behavior was disturbed during startup and stopping process. Li et al (2010) uses DSR (Dynamic Slip Region) method which are fully dynamic, closer to reality, and capable of capturing the instantaneous impeller-volute interactions. Gao et al (2013) has simulated the transient performance of the reactor coolant pump which has an excellent agreement with the Tsukamoto's experimental results.…”