Exploring a new criterion to determine the onset of cavitation in centrifugal pumps from energy-saving standpoint; experimental and numerical investigation

Energy, Journal Year: 2024, Volume and Issue: 293, P. 130681 - 130681

Published: Feb. 15, 2024

Language: Английский

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Numerical study on cavitation–vortex–noise correlation mechanism and dynamic mode decomposition of a hydrofoil

Physics of Fluids, Journal Year: 2022, Volume and Issue: 34(12)

Published: Nov. 16, 2022

The large eddy simulation model coupled with the modified Schnerr–Sauer cavitation has been used to numerically simulate unsteady and noncavitation flow of three-dimensional NACA66 (National Advisory Committee for Aeronautics) hydrofoil under different operating conditions. results show that magnitude number plays a decisive role in quasiperiodic phenomenon. 1.25 is as typical working condition analysis. Using Ffowcs Williams–Hawkings acoustic analogy approach accompanied by vorticity transport equation splitting, growth shedding also lead vortex structure. cavitation–vortex interaction mainly influenced stretching term dilatation amplitude them are larger than 500. baroclinic torque may be responsible generating during cloud collapse lower about 200. cavity volume acceleration main influencing factor low-frequency pressure fluctuation around cavitating hydrofoil. Moreover, surface-pressure data collected dynamic mode decomposition locate surface noise sources. alternate high low regions overlap highly transformation regions. fluctuations reason generation periodic source on surface. corresponding frequencies each order linearly correlated frequency 5.70 Hz. Combined multiple comparisons, it can inferred suction effect will generate waves starting from upstream moving downstream.

Language: Английский

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Dynamic mode decomposition to classify cavitating flow regimes induced by thermodynamic effects

Energy, Journal Year: 2022, Volume and Issue: 254, P. 124426 - 124426

Published: June 4, 2022

Language: Английский

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Cavitation state identification of centrifugal pump based on CEEMD-DRSN

Nuclear Engineering and Technology, Journal Year: 2023, Volume and Issue: 55(4), P. 1507 - 1517

Published: Jan. 28, 2023

Centrifugal pumps are a crucial part of nuclear power plants, and their dependable safe operation is to the security entire facility. Cavitation will cause centrifugal pump violently vibration with large number vacuoles generated, which not only affect hydraulic performance but also structural damage impeller, seriously affecting operational safety plants. A closed cavitation test bench constructed, method for precisely identifying state proposed based on Complementary Ensemble Empirical Mode Decomposition (CEEMD) Deep Residual Shrinkage Network (DRSN). First, we compared sensitivity pressure fluctuation, vibration, liquid-borne noise decomposed by CEEMD capture characteristics. The decomposition results sent into 12-layer deep residual shrinkage network (DRSN) identification training. demonstrate that signal most cavitation-sensitive signal, accuracy CEEMD-DRSN identify at different stages arrives 94.61%

Language: Английский

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A Multiscale Euler–Lagrange Model for High-Frequency Cavitation Noise Prediction

Journal of Fluids Engineering, Journal Year: 2024, Volume and Issue: 146(6)

Published: Feb. 22, 2024

Abstract To simulate the microscale bubble distribution and its effect on high-frequency cavitation noise, we present a two-way transition coupling Euler–Lagrange model. The model accounts for both cavity fission environmental nucleation as sources of bubbles, which are limited in traditional mesh-based Euler models. We evaluate with experimental data truncated NACA0009 hydrofoil well measured size distributions, showing satisfactory results velocity distribution, patterns, power law scalings size. Based an acoustic analogy, find that produces sound waves smaller wavelengths higher frequencies than model, mainly attributed to two factors: (1) bubbles high natural frequency (2) intense multiple collapse/rebound behavior. This is promising predicting full-spectrum noise.

Language: Английский

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Flow Characteristics and Pressure Pulsation Analysis of Cavitation Induced in a Double-Volute Centrifugal Pump

Water, Journal Year: 2025, Volume and Issue: 17(3), P. 445 - 445

Published: Feb. 5, 2025

Cavitation is a complex multiphase flow phenomenon, and the generation of transient phase transitions between liquid vapor during cavitation development leads to multi-scale vortex motion. The dynamics centrifugal pump’s rotor–stator interaction will induce pressure fluctuations in impeller volute fluid pump, resulting field structure. Based on Schnerr–Sauer model SST k-ω turbulence model, this paper studies characteristics cavitation-induced unsteady pump excitation response pulsation under different conditions, taking large vertical double-volute as research object. results indicate following: As rotates, external response, jet-wake structure at blade outlet shows an increase frequency signal. This evident near measurement points tongue separator. When severe occurs, maximum amplitude shifts from (30°) downstream (45°). value fpmax 3.1 times that when NPSHa = 8.88 m. By applying Omega identification method, it can be seen vortices trailing edge stable undergoes process elongation, fusion, separation, recovery. represents influence volute. Q 0.9Qd, passage tail detaching dissipating path observed, demonstrating upstream impeller.

Language: Английский

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Liquid-vapor two-phase flow in centrifugal pump: Cavitation, mass transfer, and impeller structure optimization

Vacuum, Journal Year: 2022, Volume and Issue: 201, P. 111102 - 111102

Published: April 13, 2022

Language: Английский

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Solid-liquid multiphase flow and erosion characteristics of a centrifugal pump in the energy storage pump station

Journal of Energy Storage, Journal Year: 2022, Volume and Issue: 56, P. 105916 - 105916

Published: Oct. 28, 2022

Language: Английский

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Effect of outlet impeller diameter on performance prediction of centrifugal pump under single-phase and cavitation flow conditions

International Journal of Nonlinear Sciences and Numerical Simulation, Journal Year: 2022, Volume and Issue: 23(7-8), P. 1203 - 1229

Published: Jan. 11, 2022

Abstract In this current study, the transient numerical calculations using CFD code are carried out under different outlet impeller diameters for flow field within a centrifugal pump single-phase and cavitation conditions. Both qualitative quantitative analyses on all of these results in order to better understand structure pump. Also, investigations configurations relating static pressure, velocity magnitude, vapour volume fraction variations, as well pressure fluctuations both time frequency domain at volute analysed. Velocity variations range (200, 210 220 mm) investigated. Reliable model is developed validated, various operating conditions, analyse characteristics domain. Cavitation occurrence, rates, detected correlated, (volume distributions). Based model’s findings, set conditions ranges, distribution impact (cavitation head-wises) The average fluctuation do = mm higher than 200 by about 6.74%, also maximum around 7.4%. Furthermore, 12.48%, 10.8%. models proved valuable tools identifying optimizing performance characterization. head when 14.13% 14.69%. lower 41.58%. two models. There small clearance between model, leading amplitudes being other above

Language: Английский

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Effect of water injection on the cavitation control:experiments on a NACA66 (MOD) hydrofoil

Acta Mechanica Sinica, Journal Year: 2020, Volume and Issue: 36(5), P. 999 - 1017

Published: Aug. 29, 2020

Language: Английский

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