Mechanism analyses of the unsteady vortical cavitation behaviors for a waterjet pump in a non-uniform inflow

Huang, Renfang; Wang, Yiwei; Du, Tao; Luo, Xianwu; Zhang, Wei; Dai, Yuanxing

doi:10.1016/j.oceaneng.2021.108798

Cited by 26 publications

(12 citation statements)

References 51 publications

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“…Van Esch [8] conducted an experimental study on the effect of non-uniform inflow on the performance and impeller load of a mixed flow pump, and observed that the rotor system was subjected to a very large and stable radial force. Huang R [9] conducted unsteady numerical simulation research on the transient cavitation flow of water jet pump under non-uniform inflow, predicted the hydrodynamic performance and cavitation performance well, and found that the occurrence of cavitation led to large fluctuations in hydrodynamic characteristics and non-uniformity of impeller inlet plane. Zhu D et al [10] studied the effect of leading edge cavitation on the axial force of impeller blade in the reversible pump turbine pump mode, and found that from no cavitation to critical cavitation, the axial force first increases and then rapidly decreases; And as the flow rate increases, the flow separation and pressure drop gradually shift from the suction side to the pressure side.…”

Section: Introductionmentioning

confidence: 99%

Numerical research on performance failure caused by gas blocking in multiphase mixed-transport pump under non-uniform inflow conditions

Wang,

Quan,

Feng

et al. 2024

J. Phys.: Conf. Ser.

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The helical-axial multiphase mixed-transport pump fails due to gas blocking caused by gas-liquid separation caused by cavitation under complex conditions with high gas volume fraction. This is an urgent engineering problem that needs to be addressed in the application of this pump. In order to simulate the flow structure characteristics in the channel, two types of non-uniform inflow boundary conditions were introduced. The bubble structure, velocity, and pressure under different inflow conditions were compared and analyzed, and the variation patterns affected by non-uniform boundary conditions were obtained. At the same time, the internal flow characteristics and mechanisms of multiphase mixed-transport pump are analyzed based on the velocity changes at the inlet of the impeller and the pressure fluctuations at the outlet of the guide vanes, leading to the intensification of gas-liquid separation and eventually the development of gas blocking. Research has shown that through programmatic control of the inlet boundary conditions, a linear change in inlet pressure has a more significant effect on the intensification of gas-liquid separation in the flow channel of the mixed-transport pump than a sinusoidal change, ultimately leading to significant performance failure when generating gas blocking. The research conclusion provides reference value for solving gas blocking in engineering applications of helical-axial multiphase mixed-transport pump.

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Section: Introductionmentioning

confidence: 99%

Numerical research on performance failure caused by gas blocking in multiphase mixed-transport pump under non-uniform inflow conditions

Wang,

Quan,

Feng

et al. 2024

J. Phys.: Conf. Ser.

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“…The results revealed that large positive incidence angles near the blade inlet were the main cause of local separation, leading to a significant decrease in the water-jet pump's head [3]. Huang et al based on boundary vorticity analysis, investigated the characteristics of transient vortex cavitation in water-jet pumps under nonuniform inflow conditions and identified cavitation as an important mechanism for boundary vortex diffusion [4]. Bai et al examined the spatial evolution of leakage vortices at the blade tip of a straight hydrofoil using vorticity, the Q-criterion, Ω method, and Liutex method.…”

Section: Introductionmentioning

confidence: 99%

Analysis of internal flow characteristics of water-jet propulsion under turning conditions

Chen,

Pan,

2024

J. Phys.: Conf. Ser.

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In order to explore the internal flow characteristics of the water-jet propulsion under turning conditions, we carried out numerical simulations of the axial-flow water-jet propulsion under different turning conditions and set up monitoring points at the inlet and outlet of the impeller to analyse the internal pressure pulsation law of the water-jet propulsion under different turning conditions. The calculation results show that the propulsion performance of the propeller decreases with the increase of the turning angle, and the left turn is better than the right turn. The vortices mainly appear around the rotor shaft, the inlet of the suction pipe and the side wall opposite to the suction pipe. The larger the turning angle, the larger the vortex area in the impeller section, while in right-hand rotation, the vortex on the suction surface decreases and the vortex on the trailing edge increases. The opposite is true for left-hand rotation. The change in pressure on the inlet surface of the impeller with the rotation angle is less pronounced compared to right-hand rotation. In addition, the pressure pulsation pattern on the impeller outlet surface is slightly improved in left-hand rotation compared to right-hand rotation.

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“…Guo [10] and Mark [11] analyzed the flow rate distribution and velocity distribution in the pump inlet under the elbow inflow condition, and found that the reasonable design of the elbow radius ratio contributed to improving the non-uniformity of the inflow. Meanwhile, the non-uniform inflow causes the increase of the critical cavitation allowance [12,13], and then an obvious asymmetry structure of the cavitation area appeared in the impeller to reduce the cavitation performance of centrifugal pump.…”

Section: Introductionmentioning

confidence: 99%

Optimization Design for the Centrifugal Pump under Non-Uniform Elbow Inflow Based on Orthogonal Test and GA_PSO

Yuan

Jin²,

Tang

et al. 2022

Processes

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The non-uniform inflow caused by the elbow inlet is one of the main reasons for the low actual operation performance of a centrifugal pump. Orthogonal experiment and GA_PSO algorithm are used to improve the head and efficiency of a centrifugal pump with an elbow inlet based on the method combining numerical simulation and prototype experiment in this paper. The effects of the design parameters, including elbow inlet radius ratio, blade inlet angle, blade number, blade wrap angle, blade outlet angle, impeller outlet diameter, blade outlet width and flow area ratio, on the pump head and efficiency are studied in the orthogonal experiment. The blade inlet angle is the major factor to match the non-uniform inflow and reduce the flow loss in the impeller inlet to contribute to enhancing the pump performance and cavitation characteristics. The particle swarm optimization (PSO) algorithm is optimized by integrating the genetic algorithm (GA), which ensures that the PSO-calculation result avoids falling into the local optimization and the global optimal solution is obtained as quickly as possible. The centrifugal pump with an elbow inlet is optimally designed by the GA_PSO algorithm. According to the performance test results, the efficiency of the optimized pump is 4.7% higher than that of the original pump.

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Mechanism analyses of the unsteady vortical cavitation behaviors for a waterjet pump in a non-uniform inflow

Cited by 26 publications

References 51 publications

Numerical research on performance failure caused by gas blocking in multiphase mixed-transport pump under non-uniform inflow conditions

Numerical research on performance failure caused by gas blocking in multiphase mixed-transport pump under non-uniform inflow conditions

Analysis of internal flow characteristics of water-jet propulsion under turning conditions

Optimization Design for the Centrifugal Pump under Non-Uniform Elbow Inflow Based on Orthogonal Test and GA_PSO

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