scholarly journals Effect of the staggered impeller on reducing unsteady pressure pulsations of a centrifugal pump

2021 ◽  
Author(s):  
Ning Zhang ◽  
Junxian Jiang ◽  
Xiaokai Liu ◽  
Bo Gao
Keyword(s):  
Centrifugal Pump ◽  
Internal Flow ◽  
Simulation Method ◽  
Low Noise ◽  
Stable Operation ◽  
Pump Efficiency ◽  
Pressure Pulsations ◽  
Pump Design ◽  
Pump Head ◽  
Rotor Stator Interaction

Abstract High pressure pulsations excited by rotor stator interaction is always focused in pumps, especially for its control considering the stable operation. In the current research, a special staggered impeller is proposed to reduce intense pressure pulsations of a centrifugal pump with ns=69 based on alleviating rotor stator interaction. The numerical simulation method is conducted to illustrate the influence of staggered impeller on the pump performance and pressure pulsations, and three typical flow rates (0.8ФN-1.2ФN) are simulated. Results show that the staggered impeller will lead to the pump head increasing, and at the design working condition, the increment reaches about 3% compared with the original impeller. Meanwhile, the pump efficiency is little affected by the staggered impeller, which is almost identical with the original impeller. From comparison of pressure spectra at twenty monitoring points around the impeller outlet, it is validated that the staggered impeller contributes significantly to decreasing pressure pulsations at the concerned working conditions. At the blade passing frequency, the averaged reduction of twenty points reaches 89% by using the staggered impeller at 1.0ФN. The reduction reaches to 90%, 80% at 0.8ФN, 1.2ФN respectively. Caused by the rib within the staggered impeller, the internal flow field in the blade channel will be affected. Finally, it is concluded that the proposed staggered impeller surely has a significant effect on alleviating intense pressure pulsation of the model pump, which is very promising during the low noise pump design considering its feasibility for manufacturing.

Effects of the staggered blades on unsteady pressure pulsations and flow structures of a centrifugal pump

2021 ◽  
pp. 095765092098732
Author(s):  
Ning Zhang ◽  
Bo Gao ◽  
Chao Li ◽  
Dan Ni ◽  
Guoping Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Pulsation ◽  
Second Harmonic ◽  
Simulation Method ◽  
Pump Efficiency ◽  
Pressure Amplitude ◽  
Pressure Pulsations ◽  
Unsteady Pressure ◽  
Negative Effect

Effects of the staggered blades on unsteady pressure pulsations of a centrifugal pump with a specific speed ns=147 are investigated by the numerical simulation method. The obtained results are compared with the original blades. To clarify the resulting effects, eight monitoring points are used to extract pressure signals at three typical working conditions, and component at the blade passing frequency fBPF is emphasized. Results show that the pump efficiency and head will be reduced by the staggered blades, and at the nominal flow rate, the reduction is about 1.5% from comparison with the original blades. For all the eight points, the staggered blades contribute to the reduction of pressure amplitudes at fBPF when the pump works at three flow rates. The averaged reduction is 15.5% at the nominal flow rate. However, the negative effect on the second harmonic of fBPF will be caused by the staggered blades, and the corresponding pressure amplitude will increase at 2fBPF. It means that the pressure pulsation energy will be redistributed among the discrete components in pressure spectrum by the staggered blades. From the TKE distribution, it is found that the TKE values on the blade pressure side will be significantly affected by the staggered blades.

scholarly journals Improvement of Internal Flow Performance of a Centrifugal Pump-As-Turbine (PAT) by Impeller Geometric Optimization

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1714
Author(s):  
Jian Xu ◽  
Longyan Wang ◽  
Stephen Ntiri Asomani ◽  
Wei Luo ◽  
Rong Lu
Keyword(s):  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Internal Flow ◽  
Geometric Optimization ◽  
Numerical Results ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Stable Operation ◽  
Operating Range ◽  
Rotor Stator Interaction

Rotor-stator interaction (RSI) in the centrifugal pump-as-turbine (PAT) is a significant source of high amplitude of the pressure pulsation and the flow-induced vibration, which is detrimental to the stable operation of PAT. It is therefore imperative to analyze the rotor-stator interaction, which can subsequently be used as a guideline for reducing the output of PAT noise, vibration and cavitation. In addition, it is important for a PAT to have a wide operating range preferably at maximum efficiency. In order to broaden the operating range, this work proposes a multi-condition optimization scheme based on numerical simulations to improve the performance of a centrifugal PAT. In this paper, the optimization of PAT impeller design variables (b2, β1, β2 and z) was investigated to shed light upon its influence on the output efficiency and its internal flow characteristics. Thus, the aim of the study is to examine the unsteady pressure pulsation distributions within the PAT flow zones as a result of the impeller geometric optimization. The numerical results of the baseline model are validated by the experimental test for numerical accuracy of the PAT. The optimized efficiencies based on three operating conditions (1.0Qd, 1.2Qd, and 1.4Qd) were maximally increased by 13.1%, 8.67% and 10.62%, respectively. The numerical results show that for the distribution of PAT pressure pulsations, the RSI is the main controlling factor where the dominant frequencies were the blade passing frequency (BPF) and its harmonics. In addition, among the three selected optimum cases, the optimized case C model exhibited the highest level of pressure pulsation amplitudes, while optimized case B reported the lowest level of pressure pulsation.

Numerical Investigation of Pressure Pulsation in Vaneless Region of a High Speed Centrifugal Pump

2019 ◽  
Author(s):  
Yongshun Zeng ◽  
Min Yang ◽  
Yuqing Zhai ◽  
Zhifeng Yao ◽  
Fujun Wang ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Pressure Pulsation ◽  
Simulation Method ◽  
Operating Conditions ◽  
Pressure Pulsations ◽  
Flow Rates ◽  
Rotor Stator Interaction ◽  
Frequency Components ◽  
Good Agreement

Abstract The pressure pulsation due to rotor-stator interaction (RSI) is unavoidable for high-speed centrifugal pump when operating under different conditions. The frequency components of pressure pulsation in the vaneless region are the most complex, and the pressure pulsation characteristic plays an important role in pump structural stress analysis. A numerical simulation method is used to obtain the hydraulic performances of a high-speed centrifugal pump with 9857 r/min at the range of flow rates between 48.1 to 155.0 m3/h. The head and efficiency under different operating conditions have good agreement with experimental results, with maximum deviations in 3.82% and 5.37%, respectively. The results show that the level of the pressure pulsation from the inlet to the outlet of the impeller increased gradually, and the pressure pulsations between the short blades are greater than that between the long and short blades. In the diffuser, the pressure pulsation is the highest near the tongue, whereas it is lower in the region between the two tongues, and this region is defined as the vaneless region. The pressure contours in the vaneless region almost have no change, while they near the tongue are densely distributed, revealing the mechanism of uneven pressure pulsation distribution. Moreover, there is a high radial velocity distribution near the tongue in the vaneless region, indicating that there may be a jet-wake pattern occured in this region.

scholarly journals Dynamic Instability Analysis of a Double-Blade Centrifugal Pump

2021 ◽  
Vol 11 (17) ◽  
pp. 8180
Author(s):  
Denghao Wu ◽  
Songbao Yao ◽  
Renyong Lin ◽  
Yun Ren ◽  
Peijian Zhou ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Dynamic Instability ◽  
Flow Instability ◽  
Design Feature ◽  
Internal Flow ◽  
Low Flow ◽  
Pressure Pulsations ◽  
Frequency Spectra ◽  
Rotor Stator Interaction ◽  
The Time Domain

The flow instability of a double-blade centrifugal pump is more serious due to its special design feature with two blades and large flow passages. The dynamic instabilities and pressure pulsations can affect the pump performance and operating lifetime. In the present study, a numerical investigation of unsteady flow and time variation of pressure within a complete double-blade centrifugal pump was carried out. The time domain and frequency domain of pressure pulsations were extracted at 16 monitoring locations covering the important regions to analyze the internal flow instabilities of the pump model. The frequency spectra of pressure pulsations were decomposed into Strouhal number dependent functions. This led to the conclusion that the blade passing frequency (BPF) related vibrations are exclusively flow-induced. Large vortices were observed in the flow passages of the pump at low flow rate. It is noted that high vorticity magnitude occurred in the vicinities of the blade trailing edge and tongue of the volute, due to the rotor-stator interaction between impeller and volute.

Effect of Surfactant Additives on Centrifugal Pump Performance

2003 ◽  
Author(s):  
Satoshi Ogata ◽  
Keizo Watanabe ◽  
Asano Kimura
Keyword(s):  
Centrifugal Pump ◽  
Surfactant Concentration ◽  
Tap Water ◽  
Maximum Flow ◽  
Pump Efficiency ◽  
Optimal Temperature ◽  
Pump Performance ◽  
Surfactant Solutions ◽  
Pump Head ◽  
Shaft Power

Performance of a centrifugal pump when handling surfactant solutions was measured experimentally. The effects of the concentration and temperature of surfactant solutions on pump performance were investigated. It was clarified that the pump efficiency with surfactant solutions was higher than that with tap water, and increased with an increase of surfactant concentration. The value of maximum flow rate of the pump also increased. The total pump head increased with an increase in the surfactant concentration, however, the shaft power decreased with a decrease in the rotational speed of the impeller. The pump efficiency is dependent on the surfactant temperature, and there is an optimal temperature which maximizes the efficiency.

scholarly journals Effect of Blade Thickness on Internal Flow and Performance of a Plastic Centrifugal Pump

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Zhenfa Xu ◽  
Fanyu Kong ◽  
Lingfeng Tang ◽  
Mingwei Liu ◽  
Jiaqiong Wang ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Variable Thickness ◽  
Internal Flow ◽  
Constant Thickness ◽  
Element Analysis ◽  
Pump Performance ◽  
Blade Thickness ◽  
The Finite Element Analysis ◽  
Pump Head ◽  
And Performance

Blade thickness is an essential parameter of the impeller, which has significant effects on the pump performance. The plastic pump generally adopts thick blade due to low strength of plastic. The effects of blade thickness on the internal flow and performance of a plastic centrifugal pump were discussed based on the numerical methods. Two kinds of blade profile, the constant thickness blade (CTB) and the variable thickness blade (VTB), were investigated. The results indicated that, for the CTB, when the blade thickness was less than 6 mm, the pump performance did not change significantly. When the blade thickness exceeded 6 mm, the pump head and efficiency decreased rapidly. The pump head and efficiency of CTB 10 decreased by 42.2% and 30% compared with CTB 4, respectively. For the VTB, with blade thickness in a certain range (6 mm–14 mm), the pump performance changed slightly with the increased of trailing edge thickness. The minimum blade thickness of the plastic centrifugal pump should be 4 mm based on the finite element analysis. A variable thickness blade (VTB 4-8-4) with the maximum thickness located at 60% chord length was proposed to improve the pump performance, and its efficiency was 1.67% higher than that of the CTB 4 impeller.

A Design Method of Aero Fuel Centrifugal Pump with Integrated Inducer and Impeller

2014 ◽  
Vol 680 ◽  
pp. 303-306
Author(s):  
Jia Li ◽  
Hua Cong Li ◽  
Jiang Feng Fu ◽  
Shu Hong Wang
Keyword(s):  
Centrifugal Pump ◽  
Simulation Analysis ◽  
Design Method ◽  
Internal Flow ◽  
Field Performance ◽  
Simulation Method ◽  
Hybrid Network ◽  
Control Technique ◽  
Pressure Side ◽  
Flow Conditions

With the development of the aero engine control technique, aero fuel centrifugal pump with integrated inducer and impeller meet the requirements better than the divided pump. This paper established the hybrid network of the centrifugal pump which adopted multi-block topology structure and octree format, analyzed the internal flow field performance of the pump based on numerical simulation. The simulation datas compared with test datas show that under different calculation conditions, head error of the simulation data and experimental data is less than 1%, and the efficiency value of error is less than 5%. The simulation method can accurately calculate the performance of the pump. The simulation analysis shows that the asymmetry of the impeller internal pressure is appreciable under different flow conditions because of the inlet length, under other small flow conditions. The most dramatic change is the pressure in the impeller channel, and the pressure under large flow conditions is lower than that under other flow conditions. In fixed location of the pressure side, there may produce low speed flow group, the situation is the same as in the entrance to the attachment of back pressure side.

Effect of Surfactant Additives on Centrifugal Pump Performance

2005 ◽  
Vol 128 (4) ◽  
pp. 794-798 ◽  
Author(s):  
Satoshi Ogata ◽  
Asano Kimura ◽  
Keizo Watanabe
Keyword(s):  
Centrifugal Pump ◽  
Energy Savings ◽  
Tap Water ◽  
Maximum Flow ◽  
Pipeline System ◽  
Pump Efficiency ◽  
Rotating Speed ◽  
Surfactant Solutions ◽  
Pump Head ◽  
Shaft Power

Performance of a centrifugal pump when handling surfactant solutions was measured experimentally. It was clarified that the pump efficiency with surfactant solutions was higher than that with tap water and increased with an increase in surfactant concentration. The value of maximum flow rate also increased. The total pump head increased with an increase in concentration, and the shaft power decreased with a decrease in the impeller rotating speed. There was an optimal temperature, which maximizes the efficiency. By combining the data for the piping section and for the pump efficiency, it is possible to accurately predict the energy savings of the pumping power in the pipeline system.

Experimental Investigation on Unsteady Pressure Pulsation in a Centrifugal Pump With Special Slope Volute

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Ning Zhang ◽  
MinGuan Yang ◽  
Bo Gao ◽  
Zhong Li ◽  
Dan Ni
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
High Amplitude ◽  
Operating Conditions ◽  
Stable Operation ◽  
Flow Induced Vibration ◽  
Unsteady Pressure ◽  
Rotor Stator Interaction ◽  
Nonlinear Components

Rotor–stator interaction, a major source of high amplitude pressure pulsation and flow-induced vibration in the centrifugal pump, is detrimental to stable operation of pumps. In the present study, a slope volute is investigated to explore an effective method to reduce high pressure pulsation level, and its influence on flow structures is analyzed using numerical simulation. The stress is placed on experimental investigation of unsteady pressure pulsation inside the slope volute pump. For that purpose, pressure pulsations are extracted at nine locations along the slope volute casing covering sensitive pump regions. Results show that distinct pressure pulsation peaks at fBPF, together with nonlinear components are captured. These peaks are closely related to the position of pressure transducer and operating conditions of the pump. The improvement of rotational speed of the impeller results in rapid increase of pressure fluctuation amplitude at fBPF and corresponding root mean square (RMS) value within 10–500 Hz. A comparison with conventional spiral volute pump is implemented as well, and it is demonstrated that slope volute contributes significantly to the decline of pressure pulsation level.

An Investigation on Mechanical Energy Supply in Rotating Flow Passage of Centrifugal Pump

2003 ◽  
Author(s):  
Takaharu Tanaka
Keyword(s):  
Centrifugal Pump ◽  
High Efficiency ◽  
Mechanical Energy ◽  
Internal Flow ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Theoretical Design ◽  
Pump Head ◽  
Definition Of ◽  
Very High

Centrifugal pump is a typical turbomachinery, which transfers mechanical energy to hydraulic energy through the rotational motion of impeller blades. It is commonly used and generally operated at a very high efficiency. Therefore, it would seem that theoretical discussion of performance and experimental observations of internal flow conditions inside the pump should be fully understood by now. However, it appears that neither the basic expressions nor the theoretical design methods are that clear. For example, the most fundamental definition of pump head, which is the most important equation in pump textbooks, is not often well explained. The purpose of this oral presentation is to share preliminary results of on-going studies on the energy transfer in centrifugal pumps.

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