Using specific speed and standard basic parameters select single-stage and double-acting centrifugal pump

The function and effectiveness of the inlet guide vanes to control the blower output and power requirements are examined. Calculated and experimental results of the power reduction by means of guide vanes are presented. The concept of the “Inlet Specific Speed” widely used in centrifugal pump field is discussed in application to the blowers. A method of estimating the performance of single-stage blowers for any position of the guide vanes is suggested. A “casing characteristic” is introduced for this purpose and its utility for the calculation of the impeller diameter for a reduction of the output is demonstrated. The performance of the inlet vanes of multistage blowers is reviewed.

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Theory and application of two-dimension viscous hydraulic design of the ultra-low specific-speed centrifugal pump

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650919850420 ◽

2019 ◽

Vol 234 (1) ◽

pp. 58-71 ◽

Cited By ~ 3

Author(s):

Cong Wang ◽

Yongxue Zhang ◽

Hucan Hou ◽

Zhiyi Yuan

Keyword(s):

Boundary Layer ◽

Centrifugal Pump ◽

Diagnostic Model ◽

Two Dimension ◽

Cavitation Performance ◽

Hydraulic Design ◽

Displacement Thickness ◽

Low Specific Speed ◽

Specific Speed ◽

Low Efficiency

Low efficiency and bad cavitation performance restrict the development of the ultra-low specific-speed centrifugal pump (ULSSCP). In this research, combined turbulent boundary layer theory with two-dimension design and two-dimension viscous hydraulic design method has been proposed to redesign a ULSSCP. Through the solution of the displacement thickness in the boundary layer, a less curved blade profile with a larger outlet angle was obtained. Then the hydraulic and cavitation performance of the reference pump and the designed pump were numerically studied. The comparison of performance of the reference pump calculated by the numerical and experimental results revealed a better agreement. Research shows that the average hydraulic efficiency and head of the designed pump improve by 2.9% and 3.3%, respectively. Besides, the designed pump has a better cavitation performance. Finally, through the internal flow analysis with entropy production diagnostic model, a 24.8% drop in head loss occurred in the designed pump.

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Optimal hydraulic design of an ultra-low specific speed centrifugal pump based on the local entropy production theory

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650918825408 ◽

2019 ◽

Vol 233 (6) ◽

pp. 715-726 ◽

Cited By ~ 3

Author(s):

Hucan Hou ◽

Yongxue Zhang ◽

Xin Zhou ◽

Zhitao Zuo ◽

Haisheng Chen

Keyword(s):

Entropy Production ◽

Centrifugal Pump ◽

Orthogonal Design ◽

High Energy ◽

Geometrical Parameters ◽

Production Theory ◽

Local Entropy ◽

Hydraulic Design ◽

Low Specific Speed ◽

Specific Speed

The ultra-low specific speed centrifugal pump has been widely applied in aerospace engineering, metallurgy, and other industrial fields. However, its hydraulic design lacks specialized theory and method. Moreover, the impeller and volute are designed separately without considering their coupling effect. Therefore, the optimal design is proposed in this study based on the local entropy production theory. Four geometrical parameters are selected to establish orthogonal design schemes including blade outlet setting angle, wrapping angle volute inlet width, and throat area. Subsequently, a 3D steady flow with Reynolds stress turbulent model and energy equation model is numerically conducted and the entropy production is calculated by a user-defined function code. The range analysis is made to identify the optimal scheme indicating that the combination of local entropy production and orthogonal design is feasible on pump optimization. The optimal pump is visibly improved with an increase of 1.08% in efficiency. Entropy production is decreased by 16.75% and 6.03% in impeller and volute, respectively. High energy loss areas are captured and explained in terms of helical vortex and wall friction, and the turbulent and wall entropy production are respectively reduced by 3.82% and 14.34% for the total pump.

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Comparative Study on Turbulence Models of High-Speed Centrifugal Pump with Low Specific Speed

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/740/1/012038 ◽

2020 ◽

Vol 740 ◽

pp. 012038

Author(s):

Xiaoyu Li ◽

Yunguang Ji ◽

Hongbin Cui ◽

Shuqi Xue

Keyword(s):

Comparative Study ◽

Centrifugal Pump ◽

High Speed ◽

Turbulence Models ◽

Low Specific Speed ◽

Specific Speed

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Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

Journal of Marine Science and Engineering ◽

10.3390/jmse9020121 ◽

2021 ◽

Vol 9 (2) ◽

pp. 121

Author(s):

Yang Yang ◽

Ling Zhou ◽

Hongtao Zhou ◽

Wanning Lv ◽

Jian Wang ◽

...

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Large Scale ◽

Internal Flow ◽

Orthogonal Test ◽

Centrifugal Pumps ◽

Initial Model ◽

Low Specific Speed ◽

Specific Speed ◽

Four Levels

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

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The effect of front streamline wrapping angle variation in a super-low specific speed centrifugal pump

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406218772605 ◽

2018 ◽

Vol 232 (23) ◽

pp. 4301-4311 ◽

Cited By ~ 3

Author(s):

Dong Liang ◽

Zhao Yuqi ◽

Liu Houlin ◽

Dai Cui ◽

Gradov D Vladimirovich ◽

...

Keyword(s):

Centrifugal Pump ◽

Pressure Pulsation ◽

Energy Performance ◽

Sweep Angle ◽

Angle Variation ◽

Noise Characteristics ◽

Ansys Cfx ◽

Low Specific Speed ◽

Specific Speed ◽

Element Method

In this research, super-low specific speed centrifugal pump ( ns = 25, Chinese units: ns = 3.6 nQ1/2/ H3/4) is studied. The effect of the front streamline wrapping angles variation (135°, 139° and 145°) of the turbine on energy performance is considered. The pressure pulsation, interior and exterior noise characteristics and the performance of the impeller are thoroughly evaluated both experimentally and numerically. The pump has been modeled by means of computational fluid dynamics code of commercial software ANSYS CFX 11.0 to estimate energy performance and pressure pulsation. Boundary element method and finite element method are used to investigate the interior and exterior noise characteristics of the centrifugal pump by varying the front sweep angle. The front sweep angle variation was found to have insignificant influence on centrifugal pump performance characteristics. However, it influences fluid hydrodynamics around the volute tongue. In addition, the decreasing of the front streamline sweep angle slightly reduces the sound pressure level for the exterior acoustics, but the radiation distribution of the acoustic field does not change. In its turn, the modified trailing edge of the blades can reduce the peak value of the superposition decreasing the pressure pulsations at the blade passing frequency and its harmonic frequencies.

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