Experimental Investigation of Blade Rows Interactions in Contra-Rotating Axial Flow Pump

2014 ◽  
Author(s):  
Linlin Cao ◽  
Hironori Honda ◽  
Hiroaki Yoshimura ◽  
Satoshi Watanabe ◽  
Akinori Furukawa
Keyword(s):  
Pressure Fluctuation ◽  
Axial Flow ◽  
Potential Interaction ◽  
Experimental Investigations ◽  
Cavitation Performance ◽  
Rotor Stator Interaction ◽  
Frequency Components ◽  
Axial Flow Pump ◽  
Theoretical Analyses ◽  
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 performance, while in our previous researches, our prototype rotors designed with equal rotational speeds for both the front and the rear rotors was also confirmed with the strong potential interaction between two blade rows. In the present study, the experimental investigations were focused on the rotor-rotor interactions in the contra-rotating rotors under two rotational speed combinations, an equal speed and a different speed ones with the lower speed of rear rotor; the latter is determined aiming at relieved rotor-rotor interaction. As the major experimental approach, casing wall static pressure measurements were conducted at pressure taps covering from upstream to downstream of the both rotors, and the pressure fluctuation modes were investigated by the FFT analyses. By series of pressure taps with different peripheral locations prepared at several axial locations, the pressure fluctuation modes with frequencies non-synchronous to the BPF (blade passing frequency) components were recognized, and confirmed to be related to the rotor-rotor interaction on the basis of theoretical analyses on the rotor-stator interaction in conventional rotor-stator types.

Experimental and Numerical Investigation on Pressure Fluctuation of the Impeller in an Axial Flow Pump

2019 ◽  
Author(s):  
Xi Shen ◽  
Desheng Zhang ◽  
Bin Xu ◽  
Yongxin Jin ◽  
Xiongfa Gao
Keyword(s):  
Pressure Fluctuation ◽  
High Speed ◽  
Axial Flow ◽  
Suction Side ◽  
High Speed Photography ◽  
Detached Eddy Simulation ◽  
Transient Pressure ◽  
Unstable Flow ◽  
Axial Flow Pump ◽  
Flow Pump

Abstract The Detached Eddy Simulation (DES) has been used to simulate the pressure fluctuation of the impeller in an axial flow pump. The results were combined with experiments including high-speed photography and transient pressure measurements to investigate the unstable flow induced by tip leakage vortex (TLV). Numerical results show that maximum predictive error values of head is 2.9%, compared with experimental results. The pressure fluctuation at different monitoring points present a certain regularity, with 3 peaks and 3 troughs in a period, corresponding to the number of blades. The amplitude of pressure fluctuation at P1 (impeller inlet) is the highest among those monitoring points, where the amplitude decreases with the flow rates. The dominant frequency of pressure fluctuation at impeller under cavitation condition is the blade passing frequency (BPF). Besides, there are also N* = 6, 9, 12 and other more harmonic frequencies. The cavitation flow was analyzed with the pressure fluctuation of the blade tip. For the existence of the pressure difference between pressure side and suction side, the pressure at monitoring points change alternately. The amplitude of the fluctuation near tip is affected seriously by the cavitation bubbles, as the cavitation could is a low pressure region with unstable fluctuation.

scholarly journals Simulation of cavitation performance of an axial flow pump with inlet guide vanes

2016 ◽  
Vol 8 (6) ◽  
pp. 168781401665158 ◽  
Author(s):  
Weimin Feng ◽  
Qian Cheng ◽  
Zhiwei Guo ◽  
Zhongdong Qian
Keyword(s):  
Axial Flow ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Cavitation Performance ◽  
Axial Flow Pump ◽  
Flow Pump

Rotor/Stator Interactions Study under Different Operating Condition in Axial Flow Pump

2013 ◽  
Vol 456 ◽  
pp. 168-172 ◽  
Author(s):  
Wei Dong Shi ◽  
Su Qing Wu ◽  
Jie Yao
Keyword(s):  
Axial Flow ◽  
Operating Conditions ◽  
Operating Condition ◽  
Simulation Based ◽  
Rotor Stator Interaction ◽  
Unsteady Simulation ◽  
Fluctuation Amplitude ◽  
Axial Flow Pump ◽  
Flow Pump ◽  
Interaction Phenomenon

Rotor/Stator interaction in axial-flow pump is the main reason for pressure fluctuates, which impacts on operating security of axial flow pump. In order to study Rotor/Stator interaction phenomenon in axial flow pump, TJ04-ZL-02 hydraulic axial flow pump model is investigated under different operating condition by unsteady simulation based on k-ω turbulence model. Numerical results show that: different flow operating conditions will lead to different Rotor/Stator interaction phenomenon, and also different pressure fluctuation. Fluctuation amplitude in design operating condition is smaller than off design operating condition. So the study proves that pump running in the design operating conditions has important beneficial to the pump operational stability.

scholarly journals CFD numerical simulation of sand-contained cavitation characteristics of axial-flow pump

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110327
Author(s):  
Peng Lin ◽  
Dong Hu ◽  
Jing-Man Lu ◽  
Shu Wang
Keyword(s):  
Particle Size ◽  
Flow Pattern ◽  
Great Influence ◽  
Axial Flow ◽  
Internal Flow ◽  
Sediment Concentration ◽  
Clean Water ◽  
Cavitation Performance ◽  
Axial Flow Pump ◽  
Flow Pump

To study the effect of sediment on the cavitation in the axial-flow pump, the method of CFD is employed to experiment on the internal flow field of the pump in the case of cavitation in clean water and sandy water separately. The calculation is done with different particle sizes and sediment concentrations. The results show that as the sediment concentration increases, the vortex range and cavitation area of the blade will further increase, and the flow pattern in the impeller becomes more disordered. The mechanism of action of particle size on cavitation is similar to that of sediment concentration. However, cavitation in clean water is quite different from that in sandy water in that the cavitation value and range in sandy water are significantly larger than that in clean water. By contrast, the particle size has little effect on the cavitation value and range. It proves that particle size does not have a great influence on cavitation distribution, but sediment concentration is the main factor affecting the cavitation performance of the pump. Moreover, sediment will disrupt the internal flow pattern of the pump, promote the development of cavitation and further reduce the cavitation performance of the pump.

On the Vortical Characteristics of Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Chaoyue Wang ◽  
Fujun Wang ◽  
Lihua Xie ◽  
Benhong Wang ◽  
Zhifeng Yao ◽  
...  
Keyword(s):  
Deformation Mechanism ◽  
Pressure Fluctuation ◽  
Vortex Tube ◽  
Axial Flow ◽  
Separation Flow ◽  
Decomposition Approach ◽  
Corner Separation ◽  
Swirling Strength ◽  
Axial Flow Pump ◽  
Flow Pump

Abstract The phenomenon of horn-like vortex in stator corner separation flow in an axial flow pump was first reported by Wang et al. (2020, “Investigation on the Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump,” ASME J. Fluids Eng., 142(7), p. 071208), and the associated external features were preliminarily presented. However, internal vortical characteristics of horn-like vortices, including the distributions of swirling strength, the deformation mechanism of vortex tube and the correlation with pressure fluctuation surge, are not revealed. In this paper, the newly developed vorticity decomposition approach is introduced, and thus more novel quantitative results are provided for the physics of horn-like vortex evolution in an axial flow pump. First, the distributions of absolute swirling strength, relative swirling strength and Liutex spectrum are presented to outline the vortical features of the horn-like vortex fields. Second, the deformation mechanism of the horn-like vortex tube is revealed. It is found that the horn-like vortex spatial evolution can be described by the deformation terms (Liutex stretching term, Liutex dilatation term, and curl term of the pseudo-Lamb vector) controlling the Liutex transport process. These terms constantly act on the horn-like vortex tube in an almost independent way, causing its continuous deformations in the transit process. Third, the quantitative correlation between horn-like vortex transit and pressure fluctuation surge is given. It is proved that periodic vortex transit can cause severe pressure fluctuation that is much larger than that induced by rotor–stator interaction. From multiple perspectives, a clearer evolution process of the horn-like vortex is outlined, which is conducive to controlling the corner separation flows and improving the stability of large-capacity and low-head pumping stations.

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