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

2021 ◽  
Author(s):  
Junxian Jiang ◽  
Ning Zhang ◽  
Xiaokai Liu ◽  
Bo Gao ◽  
Puyu Cao
Keyword(s):  
Centrifugal Pump ◽  
Pressure Pulsations ◽  
Unsteady Pressure

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.

Influence of the Blade Trailing Edge Profile on the Performance and Unsteady Pressure Pulsations in a Low Specific Speed Centrifugal Pump

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Bo Gao ◽  
Ning Zhang ◽  
Zhong Li ◽  
Dan Ni ◽  
MinGuan Yang
Keyword(s):  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Pressure Pulsations ◽  
Trailing Edge ◽  
Unsteady Pressure ◽  
Pulsation Amplitude ◽  
Trailing Edges ◽  
Edge Profile ◽  
Low Specific Speed ◽  
Specific Speed

The blade trailing edge profile is of crucial importance for the performance and pressure pulsations of centrifugal pumps. In the present study, numerical investigation is conducted to analyze the effect of the blade trailing edge profile influencing the performance and unsteady pressure pulsations in a low specific speed centrifugal pump. Five typical blade trailing edges are analyzed including original trailing edge (OTE), circle edge (CE), ellipse on pressure side (EPS), ellipse on suction side (ESS), and ellipse on both sides (EBS). Results show that the well-designed blade trailing edges, especially for the EPS and EBS profiles, can significantly improve the pump efficiency. Pressure amplitudes at fBPF and 2fBPF are together calculated to evaluate the influence of the blade trailing edge profile on pressure pulsations. The EPS and EBS profiles contribute obviously to pressure pulsations reduction. In contrast, the CE and ESS profiles lead to increase of pressure pulsation amplitude compared with the OTE pump. Vorticity distribution at the blade trailing edge demonstrates that the EPS and EBS profiles have an effective impact on reducing vortex intensity at the blade trailing edge. Consequently, rotor–stator interaction could be attenuated leading to lower pressure pulsation amplitude. It is thought to be the main reason of pressure pulsations reduction obtained with the proper modified blade trailing edges. The results would pave the way for further optimization of the blade trailing edge profile.

Effect of the volute tongue cut on pressure pulsations of a low specific speed centrifugal pump

2020 ◽  
Vol 32 (4) ◽  
pp. 758-770 ◽  
Author(s):  
Ning Zhang ◽  
Bo Gao ◽  
Bin Xia ◽  
Qi-feng Jiang
Keyword(s):  
Centrifugal Pump ◽  
Pressure Pulsations ◽  
Low Specific Speed ◽  
Specific Speed

Unsteady Flow Structure on a Centrifugal Pump: Experimental and Numerical Approaches

2002 ◽  
Author(s):  
Jose´ Gonza´lez ◽  
Carlos Santolaria ◽  
Eduardo Blanco ◽  
Joaqui´n Ferna´ndez
Keyword(s):  
Numerical Model ◽  
Centrifugal Pump ◽  
Pressure Field ◽  
Pressure Fluctuations ◽  
Side Wall ◽  
Relative Effect ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
Blade Passing Frequency ◽  
Wide Range

Both experimental and numerical studies of the unsteady pressure field inside a centrifugal pump have been carried out. The unsteady patterns found for the pressure fluctuations are compared and a further and more detailed flow study from the numerical model developed will be presented in this paper. Measurements were carried out with pressure transducers installed on the volute shroud. At the same time, the unsteady pressure field inside the volute of a centrifugal pump has been numerically modelled using a finite volume commercial code and the dynamic variables obtained have been compared with the experimental data available. In particular, the amplitude of the fluctuating pressure field in the shroud side wall of the volute at the blade passing frequency is successfully captured by the model for a wide range of operating flow rates. Once the developed numerical model has shown its capability in describing the unsteady patterns experimentally measured, an explanation for such patterns is searched. Moreover, the possibilities of the numerical model can be extended to other sections (besides the shroud wall of the volute), which can provide plausible explanations for the dynamic interaction effects between the flow at the impeller exit and the volute tongue at different axial positions. The results of the numerical simulation are focused in the blade passing frequency in order to study the relative effect of the two main phenomena occurring at that frequency for a given position: the blade passing in front of the tongue and the wakes of the blades.

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.

Blade Thickness Redesign to Improve Efficiency and Decrease Unsteady Pressure Pulsation of a Low Specific Speed Centrifugal Pump

2021 ◽  
Author(s):  
Chengshuo Wu ◽  
Peng Wu ◽  
Dazhuan Wu
Keyword(s):  
Energy Loss ◽  
Secondary Flow ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Dynamic Performance ◽  
Entropy Generation Rate ◽  
Pressure Pulsations ◽  
Blade Thickness ◽  
Low Specific Speed ◽  
Specific Speed

Abstract The existence of secondary flow in the impeller brings extra energy loss and aggravates the pressure pulsation which will worsen the hydraulic and dynamic performance of the pump. In this paper, based on the forces balance in the direction perpendicular to the streamline, an optimal design method for the blade thickness of a low specific speed centrifugal pump is proposed to suppress the secondary flow in the impeller. The origin impellers with 5 and 7 cylinder blades are redesigned and the hydraulic and dynamic performance of the model pump are investigated by numerical simulation and experimental. Results show that the blade modification proposed in this paper can effectively improve the efficiency of the model pump and reduce the internal pressure pulsations. The internal flow analysis shows that the performance improvement attributes to the suppression of secondary flow in the impeller. And the entropy generation rate is introduced to measure and locate the loss in the pump. Results show that on the one hand, the suppression of secondary flow can reduce the energy loss in the pump and improve the efficiency; on the other hand, it can repress the jet wake structure at impeller outlet and alleviate the intensity of pressure pulsations.

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