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

1987 ◽  
Vol 53 (496) ◽  
pp. 3682-3690 ◽  
Author(s):  
Sumio SAITO
Keyword(s):  
Pressure Fluctuations ◽  
Axial Flow ◽  
Axial Flow Pump ◽  
The Relationship ◽  
Flow Pump

Influence of tip clearance on pressure fluctuations in an axial flow pump

2016 ◽  
Vol 30 (4) ◽  
pp. 1603-1610 ◽  
Author(s):  
Jianjun Feng ◽  
Xingqi Luo ◽  
Pengcheng Guo ◽  
Guangkuan Wu
Keyword(s):  
Pressure Fluctuations ◽  
Axial Flow ◽  
Tip Clearance ◽  
Axial Flow Pump ◽  
Flow Pump

Investigation on the Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Chaoyue Wang ◽  
Fujun Wang ◽  
Yuan Tang ◽  
Benhong Wang ◽  
Zhifeng Yao ◽  
...  
Keyword(s):  
Guide Vane ◽  
Pressure Fluctuations ◽  
Axial Flow ◽  
Maximum Amplitude ◽  
Separation Flow ◽  
Suction Surface ◽  
Corner Separation ◽  
Axial Flow Pump ◽  
Velocity Moment ◽  
Flow Pump

Abstract Stator corner separation flow existing in the guide-vane domain has significant effects on the characteristics of an axial-flow pump. The objective of this paper is to investigate the vortical structures in stator corner separation flow. Transient numerical simulation with a proof experiment was conducted for an axial-flow pump. Structural features of the vortices and their effects on velocity moment attenuation and pressure fluctuations in the guide-vane domain were analyzed. Horn-like vortices are found in the stator corner separation flow. A full cycle of the horn-like vortex evolution, “inception-growth-development-decay,” is presented. During this transit process, the vortex tube is gradually elongated and deformed, which forms an oblique separation line on the vane suction surface. High velocity moment always exists in the flow passages of the guide-vane domain, and the uniformity of main flows is gradually reduced. Meanwhile, periodic pressure fluctuations arise. The maximum amplitude of pressure fluctuations in the flow passages occurs in the region where the horn-like vortex cores at the “growth” stage lie in, which is approximately 3.39 times higher than that in the vaneless region between the impeller and guide-vane. The dominant frequency of pressure fluctuations in the flow passages is approximately 0.75 times the rotating frequency, which is close to the frequency of the full cycle of the horn-like vortex evolution. Horn-like vortices have remarkable effects on the flow fields, and more attention should be paid to them.

scholarly journals Effect of Guide Vanes on Flow and Vibroacoustic in an Axial-Flow Pump

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Guoping Li ◽  
Eryun Chen ◽  
Ailing Yang ◽  
Zhibin Xie ◽  
Gaiping Zhao
Keyword(s):  
Guide Vane ◽  
Spectral Characteristics ◽  
Pressure Fluctuations ◽  
Axial Flow ◽  
Coupled Model ◽  
Sound Field ◽  
Pump Design ◽  
Flow Discharge ◽  
Axial Flow Pump ◽  
Flow Pump

An effect of guide-vane numbers on pressure fluctuations and structural vibroacoustics induced by unsteady flow is performed by a hybrid numerical method. A 3D flow field is simulated in axial-flow pump with four impeller blades, in which three diffuser models with 5, 7, and 9 vanes are devised to match, respectively. A full scale structural vibroacoustics coupled model is solved using LMS acoustics software. The results show that the blade-passing frequency (BPF) is dominated frequency of the vibration acceleration of pump, which is consistent with frequency spectral characteristics of pressure pulsation. The unsteady pressure fluctuating becomes strong as the flow discharge decreases from 1.0Qv to 0.6Qv, the circumferential unsteady behavior of which is more severe due to flow nonuniformity induced by the suction elbow at partial operation. Generally, the pressure fluctuating increases slightly when the flow discharge increases from 1.0Qv to 1.3Qv. Moreover, pressure fluctuations amplitude on the pump with 9-vane diffuser is small relative to other two models and the vibrating accelerating and radiation sound field at BPF are also slight relatively, which indicates that appropriate guide-vane numbers contribute to suppress pressure fluctuations and vibroacoustics in axial-flow pump. The conclusions in the present paper can provide theoretical guidance for low vibration pump design.

Numerical Investigation of Influence of Rotor-Rotor Gap on Performances of Contra-Rotating Axial Flow Pump

2015 ◽  
Author(s):  
Linlin Cao ◽  
Satoshi Watanabe ◽  
Akinori Furukawa ◽  
Dazhuan Wu
Keyword(s):  
Pressure Fluctuations ◽  
Axial Flow ◽  
Internal Flow ◽  
Numerical Approach ◽  
Flow Structures ◽  
Flow Properties ◽  
Rotating Blade ◽  
Axial Flow Pump ◽  
Potential Interactions ◽  
Flow Pump

As a high specific speed pump, the contra-rotating axial flow pump with two rotors rotating reversely has been proved with higher hydraulic and cavitation performances. However, while compared with the traditional rotor-stator combination, it suffers from more significant potential interactions between two rotating blade rows, and the gap between two rotors has to be kept large with accepting the small deterioration of head performance. In our previous studies, the different speed design was confirmed effective to weaken the blade rows interactions, and therefore indicated the possibility to pertinently reduce the gap between two rotors as well as improve the hydraulic performances of the contra-rotating axial flow pump. The present paper majorly discuss the possibility to further improve the hydraulic performances of contra-rotating axial flow pump by reducing the gap between two blade rows. The cases with original gap, increased gap and reduced gap were studied by the numerical approach. The internal flow structures between two blade rows were concentrated, and a simplified method for the pressure fluctuations investigation was applied. This study is supposed to offer more understanding about the internal flow properties and give more guidelines to determine the related parameters for contra-rotating rotor-rotor combination.

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

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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