scholarly journals Effect of the Impeller Outlet Angle on Radial Thrust of Single-Blade Centrifugal Pump(Fluids Engineering)

2009 ◽  
Vol 75 (760) ◽  
pp. 2479-2487 ◽  
Author(s):  
Yasuyuki NISHI ◽  
Ryota FUJIWARA ◽  
Junichiro FUKUTOMI
2009 ◽  
Vol 2009 (0) ◽  
pp. 357-358
Author(s):  
Yasuyuki NISHI ◽  
Ryota FUJIWARA ◽  
Yoshikado HOTTA ◽  
Junichiro FUKUTOMI ◽  
Toru SHIGEMITSU

2012 ◽  
Vol 249-250 ◽  
pp. 460-465 ◽  
Author(s):  
Yong Wang ◽  
Jian Wang ◽  
Dong Xi Liu ◽  
Hou Lin Liu

In order to research the effects of impeller outlet angles on flow induced vibration and noise of centrifugal pumps, a single grade end suction centrifugal pump is employed as a research object. The outlet angles were varied from 33° to 29°and 37°, but the volute and the other geometric parameters keep constant. Based on the virtual instrument data acquisition system, pump product testing system and in the centrifugal pump closed experimental rig, the flow induced vibration and noise signals of model pump with different outlet angles in the full flow range are measured and analyzed. Experimental results show that the influence of flow induced vibration on volute is the largest. With the increase of impeller outlet angle, the variation tendency of vibration intensity for 4 measure points decrease. The vibration intensity of model pump gets the minimum value, when the outlet angle is 37°. Under different conditions, the shaft frequency peak of noise signal varied intricately with the increase of impeller outlet angle. When the outlet angle is 33°, the shaft frequency peak of the model pump is relatively small under each operating condition, and gets the minimum value at the design condition.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Yasuyuki Nishi ◽  
Junichiro Fukutomi

Geometrically, the single-blade centrifugal impeller, commonly used today as a sewage pump, is not axially symmetric. For this reason, the static pressure around the impeller fluctuates greatly when the impeller is rotating, and not only the radial thrust but also the axial thrust shows large fluctuations. Therefore, it is extremely important for the improvement of pump reliability to quantitatively grasp these fluctuating hydrodynamic forces. In this study, we investigated the unsteady hydrodynamic forces in a closed-type centrifugal pump with a single blade for different blade outlet angles using a numerical analysis that takes into account both experiment and the leakage flow. The results clearly showed the effect of the blade outlet angle on that act on the impeller. The root-mean-square value of the fluctuating component of the total radial thrust was roughly the same for whichever impeller at low flow rate, but at high flow rates, the value increased for impellers with larger blade outlet angles. Moreover, when the leakage flow rate increased with increasing static pressure around the impeller, such that the rear and front shroud parts were subject to high pressure, the absolute value of the axial thrust on both these parts increased.


Vacuum ◽  
2019 ◽  
Vol 159 ◽  
pp. 239-246 ◽  
Author(s):  
Hongchang Ding ◽  
Zikang Li ◽  
Xiaobin Gong ◽  
Maoshun Li

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1408 ◽  
Author(s):  
Bin Huang ◽  
Guitao Zeng ◽  
Bo Qian ◽  
Peng Wu ◽  
Peili Shi ◽  
...  

The pressure fluctuation inside centrifugal pumps is one of the main causes of hydro-induced vibration, especially at the blade-passing frequency and its harmonics. This paper investigates the feature of blade-passing frequency excitation in a low-specific-speed centrifugal pump in the perspective of local Euler head distribution based on CFD analysis. Meanwhile, the relation between local Euler head distribution and pressure fluctuation amplitude is observed and used to explain the mechanism of intensive pressure fluctuation. The impeller blade with ordinary trailing edge profile, which is the prototype impeller in this study, usually induces wake shedding near the impeller outlet, making the energy distribution less uniform. Because of this, the method of reducing pressure fluctuation by means of improving Euler head distribution uniformity by modifying the impeller blade trailing edge profile is proposed. The impeller blade trailing edges are trimmed in different scales, which are marked as model A, B, and C. As a result of trailing edge trimming, the impeller outlet angles at the pressure side of the prototype of model A, B, and C are 21, 18, 15, and 12 degrees, respectively. The differences in Euler head distribution and pressure fluctuation between the model impellers at nominal flow rate are investigated and analyzed. Experimental verification is also conducted to validate the CFD results. The results show that the blade trailing edge profiling on the pressure side can help reduce pressure fluctuation. The uniformity of Euler head circumferential distribution, which is directly related to the intensity of pressure fluctuation, is improved because the impeller blade outlet angle on the pressure side decreases and thus the velocity components are adjusted when the blade trailing edge profile is modified. The results of the investigation demonstrate that blade trailing edge profiling can be used in the vibration reduction of low specific impellers and in the engineering design of centrifugal pumps.


2011 ◽  
Vol 4 (4) ◽  
pp. 387-395 ◽  
Author(s):  
Yasuyuki Nishi ◽  
Junichiro Fukutomi ◽  
Ryota Fujiwara

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 126
Author(s):  
Houlin Liu ◽  
Ruichao Xia ◽  
Kai Wang ◽  
Yucheng Jing ◽  
Xianghui He

Experimental measurements to analyze the pressure fluctuation performance of a centrifugal pump with a vaned-diffuser, which its specific speed is 190. Results indicate that the main cause of pressure fluctuation is the rotor-stator interference at the impeller outlet. The head of the pump with vaned-diffuser at the design flow rate is 15.03 m, and the efficiency of the pump with a vaned-diffuser at the design flow rate reaches 71.47%. Pressure fluctuation decreases gradually with increasing distance from the impeller outlet. Along with the increase of the flow rate, amplitude of pressure fluctuation decreases. The amplitude of pressure fluctuation at the measuring points near the diffusion section of the pump body is larger than other measuring points. The variation tendency of pressure fluctuation at P1–P10 is the same, while there are wide frequency bands with different frequencies. The dominant frequency of pressure fluctuation is the blade passing frequency. The rotor-stator interference between the impeller and the vaned-diffuser gives rise to the main signal source of pressure fluctuation.


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