Study on flow measurement method of vertical axial flow pump based on the relationship between flow and differential pressure of two points in elbow inlet passage

An application of contra-rotating rotors, in which a rear rotor is employed in tandem with a front one and these rotors rotate in the opposite direction each other, has been proposed against a demand for developing higher specific speed axial flow pump. The internal flow field of pump should be considered in the design for higher performance and more stable operation. The flow field in contra-rotating axial flow pump was measured with LDV and wall pressure measurements. In the present paper, the experimental results are shown and the flow behaviors would be discussed.

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The relationship between cavitation development and the velocity and pressure fluctuations of an axial-flow pump.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.53.3682 ◽

1987 ◽

Vol 53 (496) ◽

pp. 3682-3690 ◽

Cited By ~ 1

Author(s):

Sumio SAITO

Keyword(s):

Pressure Fluctuations ◽

Axial Flow ◽

Axial Flow Pump ◽

The Relationship ◽

Flow Pump

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Study on the guide impeller of large axial flow pump

International Journal of Multiphase Flow ◽

10.1016/s0301-9322(97)88558-8 ◽

1996 ◽

Vol 22 ◽

pp. 145

Author(s):

J Chen

Keyword(s):

Axial Flow ◽

Axial Flow Pump ◽

Flow Pump

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Investigation into the Influence of Division Pier on the Internal Flow and Pulsation in the Outlet Conduit of an Axial-Flow Pump

Applied Sciences ◽

10.3390/app11156774 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6774

Author(s):

Fan Yang ◽

Dongjin Jiang ◽

Tieli Wang ◽

Pengcheng Chang ◽

Chao Liu ◽

...

Keyword(s):

Velocity Distribution ◽

Pressure Pulsation ◽

Axial Flow ◽

Hydraulic Loss ◽

Main Frequency ◽

Starting Position ◽

The Difference ◽

Axial Flow Pump ◽

Outlet Conduit ◽

Flow Pump

The outlet conduit is an important construction connecting the outlet of the pump guide vane and the outlet pool; in order to study the hydraulic performance of the straight outlet conduit of the axial-flow pump device, this paper adopts the method of numerical simulation and analyzes the influence of the division pier on the pressure and velocity distribution inside and near the wall of the straight outlet conduit based on three design schemes. Four pressure pulsation measuring points were arranged in the straight outlet conduit, and the low-frequency pulsation characteristic information inside the straight outlet conduit with and without the division pier was extracted by wavelet packet reconstruction. The results show that the addition of a division pier has an effect on the hydraulic loss, near-wall pressure and velocity distribution in the straight outlet conduit. A small high-pressure zone is formed near the wall at the starting position of the division pier, and a large high-speed zone is formed on the left side at the starting position of the division pier. The length of the division pier has no significant effect on the flow distribution of the straight outlet conduit and the pressure and velocity distribution near the wall. Under different working conditions, each monitoring point has the maximum energy in the sub-band (0~31.25 Hz). With the increase of the flow rate, the total pressure energy of the straight outlet conduit decreases gradually. Under each condition, the difference of the energy proportion of the horizontal monitoring points of the straight outlet conduit is small, and the difference of the energy proportion of the two monitoring points at the top and bottom of the outlet channel is relatively large. The energy of the two monitoring points in the straight outlet conduit with a division pier is smaller than that of the two monitoring points in the straight outlet conduit without a division pier. There are differences in the main frequency and the power spectrum corresponding to the main frequency of the monitoring points in the straight outlet conduit, and the reasonable setting of the division pier is conducive to reducing the pressure pulsation of the flow in the straight outlet conduit and is beneficial to the safe and stable operation of the pump device.

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Foetal bypass: concepts and controversies

Perfusion ◽

10.1177/026765919801300206 ◽

1998 ◽

Vol 13 (2) ◽

pp. 111-117 ◽

Cited By ~ 2

Author(s):

Joseph J Sistino

Keyword(s):

Heart Defects ◽

Open Heart Surgery ◽

Axial Flow ◽

Right Atrial ◽

Cyclooxygenase Inhibitors ◽

Pump System ◽

Maternal Risk ◽

Valvular Stenosis ◽

Axial Flow Pump ◽

Flow Pump

One of the most controversial and challenging surgical undertakings of the next century promises to be foetal cardiac surgery. Animal studies have been underway for several years to gain an understanding of the physiological mechanisms required to achieve this undertaking. Not since the days of crosscirculation has there been a maternal risk associated with open-heart surgery. The diagnosis of congenital heart defects with foetal ultrasound can now be made as early as 12 weeks gestation. Simple cardiac abnormalities, such as valvular stenosis or atresia, alter intracardiac flow patterns and affect normal cardiac chamber development. Without early intervention, these complex lesions often require major surgical reconstruction, beginning in the neonatal period. Foetal cardiac bypass techniques have evolved from the use of roller pumps and bubble oxygenators primed with maternal blood to the use of an axial flow pump incorporated in a right atrial to pulmonary artery or aortic shunt. Because the blood entering the right atrium is oxygenated by the placenta, an oxygenator in the bypass circuit is probably not needed. The low prime axial flow pump system avoids the dilution of the foetus with the maternal adult haemoglobin and improves the outcome. A major focus of research has concentrated on maintenance of placental blood flow with the use of vasodilators and cyclooxygenase inhibitors. Investigation with primates will be necessary to confirm the placental physiology before human operations can be performed. As the foetal bypass challenges are overcome, there is the potential for a reduction in the number of complex cardiac lesions requiring early surgical intervention in the twenty-first century.

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