Pressure fluctuation and flow pattern of a mixed-flow pump with different blade tip clearances under cavitation condition

Xu, Ye; Tan, Lei; Liu, Yabin; Cao, Shuai

doi:10.1177/1687814017696227

Cited by 57 publications

(29 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 In contrast, the cloud cavity is eventually separated at the impeller shroud along the streamwise direction. [4][5][6][7] The cloud cavity is complex owing to the flow rates and blade geometries. [8][9][10] Among the two representative classes of the cavity, this study is focused on the former, sheet cavity.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on the cavitation phenomenon for the head drop and unsteady bubble patterns with a difference in the incidence angle of a mixed-flow pump

Kim

Yang

Suh

et al. 2020

Advances in Mechanical Engineering

View full text Add to dashboard Cite

In this study, two types of mixed-flow pump models exhibiting different suction performances were investigated to understand the cavitation characteristics of head drop gradients due to the decrease in inlet pressure. Both models were designed with the same specifications except for the shroud inlet blade angle and inlet radius which directly affect the incidence angle. The steady- and unsteady-state analyses were performed using ANSYS CFX, and the results of both models were compared. Bubble generation and patterns were systemically represented at the design flow rate to observe their influence on suction performance. Furthermore, experimental tests were performed to validate the numerical results. From the results, the head drop gradient can determine the suction performance of mixed-flow pumps. The amount and shape of the bubbles concerning the suction performance of a mixed-flow pump exhibit significant differences with the changes in time and inlet pressure. The patterns of generated bubble are not stable even for each blade.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical study on the cavitation phenomenon for the head drop and unsteady bubble patterns with a difference in the incidence angle of a mixed-flow pump

Kim

Yang

Suh

et al. 2020

Advances in Mechanical Engineering

View full text Add to dashboard Cite

show abstract

“…To compensate for the shortage of experimental methods, computational fluid dynamics (CFD) methods were used, and its predictions of cavitation behaviors in centrifugal pumps revealed interesting results. During the simulation, the Reynolds-averaged Navier-Stokes (RANS) equations coupled with a homogeneous mixture of cavitation models were applied to obtain a clearer picture of transient cavitation flow structures and pressure pulsations in both the rotating part (impeller) and stationary part (volute or vane diffusor) [7][8][9][10][11]. In addition, a number of studies focused primarily on the structural behaviors of pumps under cavitation conditions.…”

Section: Introductionmentioning

confidence: 99%

Unsteady Flow and Structural Behaviors of Centrifugal Pump under Cavitation Conditions

Ren

Mou

et al. 2019

Chin. J. Mech. Eng.

View full text Add to dashboard Cite

Cavitation has a significant effect on the flow fields and structural behaviors of a centrifugal pump. In this study, the unsteady flow and structural behaviors of a centrifugal pump are investigated numerically under different cavitation conditions. A strong two-way coupling fluid-structure interaction simulation is applied to obtain interior views of the effects of cavitating bubbles on the flow and structural dynamics of a pump. The renormalization-group k-ε turbulence model and the Zwart-Gerbe-Belamri cavitation model are solved for the fluid side, while a transient structural dynamic analysis is employed for the structure side. The different cavitation states are mapped in the head-net positive suction head (H-NPSH) curves and flow field features inside the impeller are fully revealed. Results indicate that cavitating bubbles grow and expand rapidly with decreasing NPSH. In addition, the pressure fluctuations, both in the impeller and volute, are quantitatively analyzed and associated with the cavitation states. It is shown that influence of the cavitation on the flow field is critical, specifically in the super-cavitation state. The effect of cavitation on the unsteady radial force and blade loads is also discussed. The results indicate that the averaged radial force increased from 8.5 N to 54.4 N in the transition progress from an onset cavitation state to a super-cavitation state. Furthermore, the structural behaviors, including blade deformation, stress, and natural frequencies, corresponding to the cavitation states are discussed. A large volume of cavitating bubbles weakens the fluid forces on the blade and decreases the natural frequencies of the rotor system. This study could enhance the understanding of the effects of cavitation on pump flow and structural behaviors.

show abstract

“…Cavitation also influences the characteristics of pressure fluctuations. Xu [73] found that the maximum magnitude of pressure fluctuation increases with the deteriorating cavitation induced by increasing the tip clearance in a mixed-flow pump. characteristics of pressure fluctuations.…”

Section: Pressure Fluctuationmentioning

confidence: 99%

“…characteristics of pressure fluctuations. Xu [73] found that the maximum magnitude of pressure fluctuation increases with the deteriorating cavitation induced by increasing the tip clearance in a mixed-flow pump. The above analyses illustrate that the influence of tip clearance on pressure fluctuation has various forms in terms of magnitude, frequency, and variation trends for different types of pumps and turbines, and the variation of the impact is due to the complex flow pattern in those divers machineries.…”

Section: Pressure Fluctuationmentioning

confidence: 99%

“…By contrast, Boulon et al [12] concluded that the decrease in tip clearance can reduce the cavitation-cloud size near the hydrofoil if the tip clearance is below 4 mm. Numerical results for a mixed-flow pump [73] show that increasing the tip-clearance size can increase the TLV strength and the critical-cavitation number, which exacerbates the cavitation (see Table 4 for parameters). NPSHC is the critical net positive suction head.…”

Section: Tip-clearance Sizementioning

confidence: 99%

See 1 more Smart Citation

A Review of Tip Clearance in Propeller, Pump and Turbine

2018

Self Cite

View full text Add to dashboard Cite

Propellers, pumps, and turbines are widely applied in marine equipment, water systems, and hydropower stations. With the increasing demand for energy conservation and environmental protection, the high efficiency and the stable operation of pumps and turbine have been drawing great attention in recent decades. However, the tip clearance between the rotating impeller and the stationary shroud can induce leakage flow and interact with the main stream, introducing complex vortex structures. Consequently, the energy performance and the operation stability of pumps and turbines deteriorate considerably. Constant efforts are exerted to investigate the flow mechanism of tip-clearance flow and its induced influence on performance. However, due to various pump and turbine types and the complexity of tip-clearance flow, previous works are usually focused on a specific issue. Therefore, a systematic review that synthesizes the related research is necessary and meaningful. This review investigates related research in the recent two decades in the perspectives from fundamental physics to engineering applications. Results reveal the vortex types, trajectory, evolution, and cavitation behaviors induced by tip-clearance flow. It is concluded that the influence characteristics of tip clearance on energy performance are closely related to the machinery type. Tip-clearance size and tip shape are found to be crucial parameters for tip-leakage vortex (TLV). The proposed optimization schemes are also demonstrated to provide inspiration for future research. Overall, this review article provides a coherent insight into the characteristics of tip-clearance flow and the associated engineering-design applications. On the basis of these understandings, comments on conducted research and ideas on future research are proposed.

show abstract

Pressure fluctuation and flow pattern of a mixed-flow pump with different blade tip clearances under cavitation condition

Cited by 57 publications

References 12 publications

Numerical study on the cavitation phenomenon for the head drop and unsteady bubble patterns with a difference in the incidence angle of a mixed-flow pump

Numerical study on the cavitation phenomenon for the head drop and unsteady bubble patterns with a difference in the incidence angle of a mixed-flow pump

Unsteady Flow and Structural Behaviors of Centrifugal Pump under Cavitation Conditions

A Review of Tip Clearance in Propeller, Pump and Turbine

Contact Info

Product

Resources

About