Experimental Determination of Cavitation Characteristics of Low Specific Speed Pump using Noise and Vibration

Stephen, Christopher; Kumaraswamy, S.

doi:10.1007/s40032-017-0431-5

Cited by 4 publications

(2 citation statements)

References 13 publications

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“…Cavitation will cause an increase in shaft power, a reduction in flow rate, head, and efficiency, and a decrease in thrust. At the same time, it will also cause noise and vibration in the pump [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, the Zwart model in ANSYS-CFX software was selected to simulate and analyze the cavitation process. (6) where P V is the vapor pressure; P is the flow field pressure; F vap and F cond are empirical coefficients for the vaporization and condensation processes, respectively; α ruc is the non-condensable gas fraction in the liquid; and R B is the typical bubble size in the water. According to numerous literature discussions [42][43][44], α ruc takes the value of 5 × 10 −4 ; R B takes the value of 1 × 10 −6 m; and F vap and F cond take the values 50 and 0.01, respectively.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Analysis of Two-Phase Flow in the Cavitation Process of a Waterjet Propulsion Pump System

Jiao

Cheng

Xu³

et al. 2019

Processes

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The waterjet propulsion system has been widely used in the military and civil fields because of its advantages of in terms of high efficiency and energy savings. In order to study the three-dimensional cavitation flow in the waterjet propulsion pump, the cavitation process of the waterjet propulsion pump was simulated numerically using the Zwart–Gerber–Belamri cavitation model and the RNG (Renormalization Group) k-ε model. The simulation results of cavitation on the waterjet propulsion pump and pump system show that, in the initial stage of cavitation, vapors first collect on the leading edge of the suction surface of the blade near the rim of the impeller. As the total pressure at the impeller inlet decreases, the cavitation region expands toward the trailing edge and the vapor fraction volume gradually increases. In order to simulate the cavitation state of the waterjet propulsion pump under the actual working conditions, a numerical simulation of the entire waterjet propulsion pump system with inlet passage was carried out. After assembling the inlet passage, the flow pattern at the impeller inlet becomes uneven, leading to irregular changes in the cavitation region of the impeller. The potential danger regions of cavitation are the lip of inlet passage and the upper and lower connecting curved section of the inlet passage. The performance of waterjet propulsion pump system changes greatly when the net positive suction head available (NPSHa) value of the pump reaches the critical value.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Two-Phase Flow in the Cavitation Process of a Waterjet Propulsion Pump System

Jiao

Cheng

Xu³

et al. 2019

Processes

View full text Add to dashboard Cite

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Experimental research on supercavitation in jet pump cavitation reactors for zero flow-ratio conditions

2023

Physics of Fluids

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We report an experimental study of cavitating flow in a jet pump cavitation reactor (JPCR) with a special emphasis on the supercavitation stage with a tubular supercavitation cavity. This study focuses on the evolution and characteristics of the cavitation for the zero flow-ratio conditions and the supercavitation mechanism. The results show that increasing the limiting flow ratio qr leads to shearing cavitation, which transforms into supercavitation when qr = 1. A cloud cavity forms at the end of the tubular supercavitation cavity and then sheds and collapses downstream. In addition, a wall-attached reentrant jet appears upstream. The results show that the diffuser diffusion angle β, the throat-length–diameter ratio Lth/Dth, and the throat-nozzle area ratio m all significantly affect the stability of the supercavitation cavity, with m and Lth/Dth significantly impacting the characteristic length L/Dth. The supercavitation cavity is induced by the high-speed jet entrainment and the shear layer between the jet and the surrounding water. It is then maintained by the momentum balance in the JPCR. The pressure pulsations are small in the supercavitation cavity and become significantly stronger where the cloud cavity collapses because the high-speed jet retains more energy.

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Large Eddy Simulation on the Cavitation Flow and Noise Characteristics of a NACA0009 Hydrofoil With Different Tip Clearance Sizes

Wang

Zhang

Huang

et al. 2022

Journal of Fluids Engineering

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All hydraulic machinery has a tip clearance, which not only produces tip-leakage vortexes (TLVs), but also reduces the energy performance of the machinery. In addition, tip clearance leads to cavitation and attendant vibration and noise. Therefore, investigating tip-leakage cavitating flow and noise characteristics is of great practical importance. In this paper, the energy performance and noise characteristics of NACA0009 hydrofoils with different tip clearance sizes are studied. A large eddy simulation model and Schnerr-Sauer cavitation model are employed to simulate tip-leakage cavitating flow. Additionally, a broadband noise source model and the Ffowcs Williams-Hawkings (FW-H) equation are used to calculate the noise source and far-field radiated noise characteristics, respectively. Results show that the numerical simulation of cavitation vortexand velocity field is in good agreement with the experimental data, illuminating the characteristics of energy performance, flow pattern, cavitation flow, broadband noise source, and near-field and far-field radiated noise. Compared with the original NACA0009 hydrofoil, the tip clearance reduces the noise of the Curle dipole on the hydrofoil surface and Proudman noise around the hydrofoil. Moreover, study of the far-field noise shows that the directivity curve of the overall sound pressure level (SPL) is distributed in a butterfly shape, symmetrically. Evidently, the tip clearance size has a large impact on the energy performance of the hydrofoil, the intensity of the TLV, and the cavitation. This paper lays a solid foundation for further research on cavitation flow in large-scale hydraulic machinery.

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Experimental Determination of Cavitation Characteristics of Low Specific Speed Pump using Noise and Vibration

Cited by 4 publications

References 13 publications

Numerical Analysis of Two-Phase Flow in the Cavitation Process of a Waterjet Propulsion Pump System

Numerical Analysis of Two-Phase Flow in the Cavitation Process of a Waterjet Propulsion Pump System

Experimental research on supercavitation in jet pump cavitation reactors for zero flow-ratio conditions

Large Eddy Simulation on the Cavitation Flow and Noise Characteristics of a NACA0009 Hydrofoil With Different Tip Clearance Sizes

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