Numerical analysis for the effect of tip clearance in a low specific speed mixed-flow pump

Yu, Zeting; Zhang, Wenwu; Zhu, Baoshan; Li, Yongjiang

doi:10.1177/1687814019832222

Cited by 10 publications

(5 citation statements)

References 19 publications

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“…Zhang (Zhang et al, 2017) found that, within a certain clearance range, the clearance leakage has little effect on pressure fluctuation at the impeller inlet and in the center area; beyond this range, the fluctuation of the whole flow passage increases obviously, but clearance change has little effect on the fluctuation of a guide vane. Yu et al (Yu, 2019) studied the effect of tip clearance on the performance of low-specific-speed mixed-flow pumps and found that the changes in the size of the tip clearance have a greater effect on the external performance under high flow. Anish et al (Anish and Sitaram, 2017) found that pressure fluctuation is still controlled by the blade passing frequency in the clearance.…”

Section: Introductionmentioning

confidence: 99%

Effect of Incident Angle of Wear-Ring Clearance on Pressure Pulsation and Vibration Performance of Centrifugal Pump

Jia

Li³

et al. 2022

Front. Energy Res.

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A wear-ring is an important part of the centrifugal pump. The leakage flow in the wear-ring clearance and main flow at the impeller inlet form crossed mixed flows perpendicular to each other. Large eddies and shocks are produced at the intersection of the two flows due to great velocity difference and different directions, resulting in flow losses, unsteady flow, and even flow-induced vibration. Consequently, the pump performance, pressure pulsation and vibration, and other characteristics will be greatly affected. In this paper, 5 incident angles between the incident section of the wear-ring clearance and the circumferential direction of impeller inlet, i.e., the original angle (90°), 75°, 60°, 45°, and 30°, were formed with a low-specific-speed centrifugal pump as the study object. Unsteady flow calculation and fluid–structure interaction calculation were performed on centrifugal pumps with different wear-ring clearances; the effect of the incident angle of the wear-ring clearance on the distribution of pressure pulsation and vibration performance of centrifugal pump was analyzed. The results showed that the improved efflux angle of the wear-ring clearance could effectively weaken the impact disturbance of the leakage flow in the wear-ring clearance to the main flow at the inlet. Accordingly, the flow status at the inlet of the centrifugal pump was improved, flow losses were reduced, the efficiency of the centrifugal pump was improved, and the vibration amplitude and vibration energy of the pump were also reduced.

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Section: Introductionmentioning

confidence: 99%

Effect of Incident Angle of Wear-Ring Clearance on Pressure Pulsation and Vibration Performance of Centrifugal Pump

Jia

Li³

et al. 2022

Front. Energy Res.

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“…In addition, the tip clearance enhanced the pressure fluctuation strength in the impeller, however, the effect on the pressure fluctuation in the diffuser was not obvious. Based on the finite volume method (FVM), Yu et al [25] and Zhang et al [26] applied ANSYS CFX software to probe into the effect of tip clearance on the flow patterns and pressure fluctuation characteristics in a low specific speed mixed flow pump, and pointed out the effect of tip clearance on pump performance at large flow rate was more obvious. In the meantime, the rotor and stator interaction (RSI) was the reason for the pressure fluctuation, and the TLF had less effect on the impeller inlet and middle region within a certain range.…”

Section: Introductionmentioning

confidence: 99%

Phase Distribution in the Tip Clearance of a Multiphase Pump at Multiple Operating Points and Its Effect on the Pressure Fluctuation Intensity

Shi

Liu

et al. 2021

Processes

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Tip clearance has a great effect on the flow and pressure fluctuation characteristics in a multiphase pump, especially at multiple operating points. The phase distribution and pressure fluctuation in tip clearance in a multiphase pump are revealed using the CFD (computational fluid dynamics) technology and high-speed photography methods. In this paper, the phase distribution, the gas-liquid two-phase velocity slip, and the pressure fluctuation intensity are comprehensively analyzed. Results show with the increase of the tip clearance, the multiphase pump pressurization performance is obviously deteriorated. In the meantime, the gas accumulation mainly occurs at the hub, the blade suction side (SS), and the tip clearance, and the maximum gas-liquid two-phase velocity difference is near the impeller streamwise of 0.4. In addition, the tip clearance improves the gas-liquid two-phase distribution in the pump, that is, the larger the tip clearance is, the more uniform the gas-liquid distribution becomes. Furthermore, the gas leads to the maximum pressure fluctuation intensity in the tip clearance which is closer to the tip leakage flow (TLF) outlet, and has a greater effect on the degree of flow separation in the tip clearance.

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“…Meanwhile, with the increase of tip clearance, the leakage vortex intensity is enhanced, and the separation between the main leakage vortex and the secondary leakage vortex is also strengthened. Yu, Z. et al 22 studied the effect of the tip clearance on the performance in the low specific speed mixed flow pump using numerical simulation method. It was found that the variation of the tip clearance has an effect on the external characteristics of the pump at the large flow rate.…”

Section: Introductionmentioning

confidence: 99%

Velocity characteristics in a multiphase pump under different tip clearances

Shi

Liu

Xiao

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part A:

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To investigate the effect of tip clearance on the velocity distribution in a multiphase pump, the internal flow and velocity distribution characteristics in pump under different tip clearances are studied using experimental and numerical methods. Simulations based on the Reynolds-Averaged Navier-Stokes equations (RANS) and the standard k-ε turbulence model are carried out using ANSYS CFX. Under conditions of inlet gas void fraction (IGVF) is 5% at the flow rate of 0.6Q, 0.7Q and 0.8Q (Q is the design flow rate), the accuracy of the numerical method is verified by comparing with the experimental data using high-speed photography. Results show that the leakage flow interacts with the main flow and evolves into the tip leakage vortex (TLV). Due to the TLV, the pressure, velocity, turbulent kinetic energy (TKE), vorticity and streamlines on the S2 stream surface in the impeller and diffuser are changed greatly under different tip clearances. The velocities at the impeller outlet and diffuser inlet along the radial direction are also changed. The axial velocity distribution is similar to the meridional velocity distribution at the impeller blade outlet. While the relative velocity and absolute velocity distribution show the opposite trends. In addition, the vorticity is larger near the tip separated vortex and the hydraulic loss in pump is also increased due to the TLV.

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Numerical analysis for the effect of tip clearance in a low specific speed mixed-flow pump

Cited by 10 publications

References 19 publications

Effect of Incident Angle of Wear-Ring Clearance on Pressure Pulsation and Vibration Performance of Centrifugal Pump

Effect of Incident Angle of Wear-Ring Clearance on Pressure Pulsation and Vibration Performance of Centrifugal Pump

Phase Distribution in the Tip Clearance of a Multiphase Pump at Multiple Operating Points and Its Effect on the Pressure Fluctuation Intensity

Velocity characteristics in a multiphase pump under different tip clearances

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