Theoretical Evaluation of the Effects of the Impeller Entrance Geometry and of the Incident Angle on Cavitation Inception in Centrifugal Pumps

1995 ◽  
Vol 209 (1) ◽  
pp. 29-38 ◽  
Author(s):  
G Ardizzon ◽  
G Pavesi
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Present Model ◽  
Incident Angle ◽  
Three Dimensional ◽  
Centrifugal Pumps ◽  
Theoretical Evaluation ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Comparison With Experimental Data

A method, based on quasi three-dimensional analysis, of describing pump cavitation behaviour is proposed. Cavitation performance is related to impeller entrance design and the influence of the angle of attack of the leading edges on the flow is studied. Coefficients are derived from the pressure drop due separately to the vanes and shroud. The influence of incident angle on cavitation is shown as a function of the blade geometry and discussed. By comparison with experimental data on centrifugal pumps, it is shown that the present model can simulate the characteristics of inception cavitation at design and off-design conditions.

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.

Effects of Water-Admission on the Performance of a Centrifugal Pump

2015 ◽  
Author(s):  
Xuanyu Guo ◽  
Weiping Yu ◽  
Xianwu Luo
Keyword(s):  
Centrifugal Pump ◽  
Turbulent Flows ◽  
Three Dimensional ◽  
Sudden Increase ◽  
Operation Condition ◽  
Pump Impeller ◽  
Pump Performance ◽  
Cavitation Inception ◽  
Numerical Result ◽  
Cavitation Performance

In order to improve the centrifugal pump performance at off-design operation condition, water-admission is introduced at the upstream of impeller inlet. This paper treats a centrifugal condensate pump with the specific speed of 216 min−1·m3/min·m. Both hydraulic and cavitation performance have been experimentally tested for the pump. For analysis, the three-dimensional cavitating turbulent flows are simulated based on RANS method and a homogeneous cavitation model for several water-admission cases. The results indicated that with the water-admission, the pump head and hydraulic efficiency increase with the water-admission pressure up to 70kPa. However, with the water-admission pressure larger than 70kPa, the pump performance drops due to a large flow rate induced upstream the pump impeller. It is also noted that the water admission is unfavorable for cavitation inception. According to the numerical result, there is a sudden increase of accumulated cavity volume inside the impeller with the water-admission pressure larger than 70kPa. Thus, the water-admission should be further studied to improve the cavitation performance.

Design of Pump Impellers for Optimum Cavitation Performance

1973 ◽  
Vol 187 (1) ◽  
pp. 667-678 ◽  
Author(s):  
I. S. Pearsall
Keyword(s):  
Experimental Data ◽  
Empirical Data ◽  
Potential Flow ◽  
Theoretical Basis ◽  
Theoretical Method ◽  
Cavitation Inception ◽  
Blade Number ◽  
Detail Design ◽  
Cavitation Performance ◽  
Theoretical Predictions

Although there is much empirical information on the cavitation performance of centrifugal and other types of pumps, there is very little theoretical basis for their design. Certainly these empirical data have been used to suggest certain fundamental requirements that produce pumps of good performance, but there is no scientific way of assessing the influence of such variables as blade incidence, blade number or shape of blade or passageway. A theory is presented for optimizing the geometric parameters to give the best cavitation performance or alternatively to assess the influences of working away from the design. From this, a theoretical method based on cascade data transformed into the radial plane is used for detail design for given cavitation inception conditions. Following on this, a new method has been developed for predicting cavitation performance breakdown, based on linearized potential flow theory. Comparisons are made between these theoretical predictions and experimental data obtained both at NEL and those quoted in the literature. Agreement is on the whole very good.

Three-dimensional viscoelastic simulation of coextrusion process: comparison with experimental data

2002 ◽  
Vol 41 (1-2) ◽  
pp. 144-153 ◽  
Author(s):  
Ki Byung Sunwoo ◽  
Seung Joon Park ◽  
Seong Jae Lee ◽  
Kyung Hyun Ahn ◽  
Seung Jong Lee
Keyword(s):  
Experimental Data ◽  
Three Dimensional ◽  
Process Comparison ◽  
Comparison With Experimental Data
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