Eliminating the head instability of an axial-flow pump using axial grooves

Goltz, I.; Kosyna, G.; Delgado, Antonio

doi:10.1177/0957650912466033

Cited by 8 publications

(4 citation statements)

References 8 publications

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“…Design changes at the impeller inlet can be applied to reduce the effect of inlet recirculation and improve the instability in axial pumps, successfully. Instability can be reduced by adding grooves to the inlet (Goltz et al [24][25]) or a double-entrance structure (Flores et al [26], Cao and Li [27]).…”

Section: Introductionmentioning

confidence: 99%

Düşey Milli Eksenel Bir Pompada Zamana Bağlı Akışın Deneysel Olarak İncelenmesi

CANBAZ¹,

YÜCEL

ALBAYRAK³

2023

Politeknik Dergisi

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Due to the changes in the system characteristics, pumps may have to be operated far away from the design point, such as in partload or over-load operating points. Operating the pumps far away from the design point may cause fluctuations in the flow. As a result of the fluctuations mechanical problems in the pump structure may occur. In order to overcome the problem, the operating characteristics of the pump must be determined at part load operating conditions as well as design point operating condition. In this study, flow inside a vertical shaft axial flow pump is investigated experimentally. The experimental setup is designed and constructed for the laboratory tests. The pump which is designed and manufactured is tested in the test setup. The performance of the pump is determined by measuring the flow rate, inlet and outlet pressures, rotational speed and power input of the pump. The part load and over load operating regions are determined. Pressure variations are measured at various performance points with the piezoelectric pressure transducer placed in between impeller and diffuser blade passage. Simultaneously, comparisons are made with the vibration spectrums obtained in the pump.

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Section: Introductionmentioning

confidence: 99%

Düşey Milli Eksenel Bir Pompada Zamana Bağlı Akışın Deneysel Olarak İncelenmesi

CANBAZ¹,

YÜCEL

ALBAYRAK³

2023

Politeknik Dergisi

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“…Similarly, axial-flow pumps, widely used for water transfer and supply, can also encounter this problem during operation [14][15][16][17][18][19]. The saddle-shaped unstable region should be avoided as it can result in internal flow disturbance, intensification of hydraulic vibration, and a sharp decline in efficiency [20][21][22][23]. Therefore, it is crucial to study the critical state of the saddle-shaped unstable region and develop objective criteria for identifying this state.…”

Section: Introductionmentioning

confidence: 99%

Critical State Calculation of Saddle-Shaped Unstable Region of the Axial-Flow Pump Based on Bifurcation SST k–ω Model

Pang

Huang

Yan

et al. 2023

JMSE

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This study aims to investigate the critical state of the saddle-shaped unstable region of the axial-flow pump and propose a suitable criterion for identifying this state. The bifurcation SST k–ω model considered the rotation effect is used in the present work and verified in the numerical calculation of a water jet pump. Then, it is used to simulate the critical state of the axial-flow pump. Results show that the leading-edge separation vortex generates at 0.6Qd, while the head declines only at 0.55Qd. Therefore, using the inflection point of the head-flow curve as the critical state criterion is unsuitable. In addition, the fixed monitoring point is unsuitable for identifying the critical state due to the insensitivity to the amplitude, main frequency, and periodicity changes at the critical state. Finally, to identify the critical state, it is essential to arrange a monitoring point at the leading edge of the blade suction near the shroud, which should rotate with the impeller. The critical state criterion is that the main frequency position of the pressure fluctuation signal is offset at the monitoring point, and the amplitude is increased by 10 times.

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“…Different geometries of the blade tip were employed to analyze the influence on cavitation characteristics. Goltz [14,15] investigated the structure of the rotor tip flow at different operating conditions. The spiral-type vortex breakdown was captured, which led to a rapid expansion of the clearance vortex in stream-wise, span-wise, and pitch-wise direction.…”

Section: Introductionmentioning

confidence: 99%