An Innovative Device to Suppress Performance-Curve Instability in a Mixed Flow Pump by Use of J-Groove

Kurokawa, Junichi; Saha, Sankar L.; Matsui, Jun; Imamura, Hiroshi

doi:10.1299/kikaib.66.460

Cited by 10 publications

(9 citation statements)

References 2 publications

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“…The grooves used by Goltz [2] in an axial flow pump, see Figure 1 and the grooves used by Kurokawa et al [1] in a mixed flow pump are both able to absorb the strong angular momentum of the back flow. When reaching the grooves, the backflow is forced to change the direction and loses swirl due to friction and forming vortices.…”

Section: Previous Workmentioning

confidence: 99%

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Suppression of Performance Curve Instability of an Axial‐Flow Pump by Using a Double‐Inlet‐Nozzle

Flores

Kosyna

Wulff

2008

International Journal of Rotating Machinery

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It has been shown that the sudden decrease of pump head in an axial flow pump caused by stall can be overcome by means of casing treatment. Flat axial grooves in front of the impeller break the swirl of the near-casing backflow. The disadvantage of this method is strong cavitation at the inlet of the grooves for flow rates below the stall point. In this paper another improved method to stabilize the performance curve will be presented, using a double-inlet-nozzle. At the onset of stall the initial near-casing backflow with its high swirl is lead off into the gap between both nozzles. At design conditions this double-inlet-nozzle is working as an injector, supporting the near-casing-inflow. The function of the double-inlet-nozzle is demonstrated by PIV-measurements.

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Section: Previous Workmentioning

confidence: 99%

“…Kurokawa et al [1] were the first who stabilized the performance curve of a mixed flow pump without decreasing the maximum of the pump efficiency. They formed shallow grooves within the casing wall, parallel to the pressure gradient.…”

Section: Introductionmentioning

confidence: 99%

Suppression of Performance Curve Instability of an Axial‐Flow Pump by Using a Double‐Inlet‐Nozzle

Flores

Kosyna

Wulff

2008

International Journal of Rotating Machinery

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“…When installed near the entrance of an impeller, J-groove has succeeded in suppressing the whirl of inlet flow, which made the performance-curve instability characterized by a rising head-capacity curve very stable. Thus J-groove can suppress surge without dropping the maximum efficiency in mixed flow and axial flow pumps [3] [4]. When installed at the entrance of diffuser of a centrifugal flow type, rotating stall in a vaned and a vaneless diffusers has been perfectly suppressed in the entire flow range and the pressure fluctuation has disappeared [5] [6].…”

Section: Introductionmentioning

confidence: 99%

J-Groove Technique for Suppressing Various Anomalous Flow Phenomena in Turbomachines

Kurokawa¹

2011

International Journal of Fluid Machinery and Systems

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In operating a turbomachine at off-design conditions various instabilities caused by anomalous flow phenomena occur and sometimes lead to the damage of a turbomachine. In order to avoid these phenomena various devices characteristic to each phenomenon have been developed, however they make turbomachines large-sized and cause efficiency drop. The present author has developed a very simple and innovative device, termed "J-groove," of suppressing various anomalous flow phenomena commonly by controlling the angular momentum of the main flow. It has been revealed that J-groove makes an operation of a turbomachine stable in all flow range, causes little efficiency drop, and can be easily applied to an existing machine. Here is reviewed totally the results of suppressing various anomalous flow phenomena in turbomachines.

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“…These figures were treated at the part of the suction cover as shown in Fig.6. The J-groove type treated grooves in a rectangle shape like a J-groove which was developed by Kurokawa et.al [3] . The Rayleigh step type put the grooves in radial direction on the front disk side casing.…”

Section: Introductionmentioning

confidence: 99%

Approaches to stable operation of shaftless centrifugal pump

2009

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The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. The impeller rotates under the floating condition without any control device. The floating condition of the impeller is realized by utilizing the pressure in pump casing. The pump performance and the rotational behavior of the impeller were investigated experimentally. It has found that the floating position of the impeller become quite unstable in a partial flow rate operation. And the pressure distribution at the casing wall affects the rotational posture of the impeller. This paper presents the effect of the casing treatment on the rotational posture of the impeller and the pressure distribution. The reasonable casing treatment is available for the stable rotational posture of the impeller.

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An Innovative Device to Suppress Performance-Curve Instability in a Mixed Flow Pump by Use of J-Groove

Cited by 10 publications

References 2 publications

Suppression of Performance Curve Instability of an Axial‐Flow Pump by Using a Double‐Inlet‐Nozzle

Suppression of Performance Curve Instability of an Axial‐Flow Pump by Using a Double‐Inlet‐Nozzle

J-Groove Technique for Suppressing Various Anomalous Flow Phenomena in Turbomachines

Approaches to stable operation of shaftless centrifugal pump

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