Influence of Meridian Shape on Screw-Type Centrifugal Pump Performance

2002 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka
Keyword(s):  
Centrifugal Pump ◽  
Design Method ◽  
Internal Flow ◽  
Generation System ◽  
Flow Passage ◽  
Back Flow ◽  
Pump Performance ◽  
Pressure Surface ◽  
Pressure Distributions ◽  
Complicated Configuration

A screw-type centrifugal pump with a wide flow passage has been widely used for drainage of rainwater as well as slurries and mud to avoid the flow passage blockage with the congestion of solids. Due to the complicated configuration of this pump, the design method of this pump has not been established yet. The authors succeeded in predicting the internal flow numerically by using our own grid-generation system and a commercial 3-D N-S code, TASCflow, as a solver. In this study, the internal flow has been predicted numerically at the design point on the five impellers with different hub cone shapes in order to clarify the influence of meridian shape on the pump performance. In particular, the relationships among the pump characteristics, the back flow at the blade pressure surface and the back flow from the volute casing to the impeller exit have been discussed in the numerical results on the velocity and pressure distributions.

scholarly journals Effects of the Impeller Blade with a Slot Structure on the Centrifugal Pump Performance

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1628 ◽  
Author(s):  
Hongliang Wang ◽  
Bing Long ◽  
Chuan Wang ◽  
Chen Han ◽  
Linjian Li
Keyword(s):  
Velocity Distribution ◽  
Centrifugal Pump ◽  
Deflection Angle ◽  
Fluid Velocity ◽  
Slot Width ◽  
Front Edge ◽  
Impeller Blade ◽  
Flow Passage ◽  
Pump Performance ◽  
Slot Structure

An impeller blade with a slot structure can affect the velocity distribution in the impeller flow passage of the centrifugal pump, thus affecting the pump’s performance. Various slot structure geometric parameter combinations were tested in this study to explore this relationship: slot position p, slot width b1, slot deflection angle β, and slot depth h with (3–4) levels were selected for each factor on an L16 orthogonal test table. The results show that b1 and h are the major factors influencing pump performance under low and rated flow conditions, while p is the major influencing factor under the large flow condition. The slot structure close to the front edge of the impeller blade can change the low-pressure region of the suction inlet of the impeller flow passage, thus improving the fluid velocity distribution in the impeller. Optimal slot parameter combinations according to the actual machining precision may include a small slot width b1, slot depth h of ¼ b, slot deflection angle β of 45°–60°, and slot position p close to the front edge of the blade at 20–40%.

Research on the Design Method of the Centrifugal Pump With Splitter Blades

2009 ◽  
Author(s):  
Shouqi Yuan ◽  
Jinfeng Zhang ◽  
Yue Tang ◽  
Jianping Yuan ◽  
Yuedeng Fu
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Design Method ◽  
Flow Distribution ◽  
Orthogonal Test ◽  
Operating Conditions ◽  
Test Results ◽  
Cfd Simulations ◽  
Pump Performance ◽  
Blade Number

The research on a centrifugal pump of low specific speed with splitter blades was carried out in recent years by our group, is systematically introduced in this paper. The design method is summarized also. At the beginning, based on the former L9(34) orthogonal test, Particle Imagine Velocity (PIV) tests and Computational Fluid Dynamics (CFD) simulations were carried out for several designs with different splitter blade length. Results show that for an impeller with splitter blades the “jet-wake” flow at the impeller outlet is improved, and the velocity distribution inside the impeller is more uniform. This explains that the impeller with splitter blades shows higher performance (especially in head and efficiency). Meanwhile, the numerical simulation results were compared with the test results, which confirm that, CFD technology can be used to observe inner flow distribution and forecast pump performance tendency. Later, a further L9(34) orthogonal test, which adopt the blade number as a new variable, was designed to explore the relationship between geometry parameters of splitter blade and pump performance, and corresponding CFD simulations for the flow field with volute were also done. From the test results the influence of the main design parameters on the hydraulic performance of a centrifugal pump and its reasonable value range are determined. The simulations forecasted pump performance show good consistency with that from tests at the rated point, and the simulated error at other flow rates were analyzed. Thirdly, in order to save research cost, numerical simulations were done for the full flow field including the cavity inside the volute and impeller. By analyzing the distribution law of blade torque and turbulent kinetic energy in the impeller, the value fetching principle for the splitter blade inlet diameter is presented as “the splitter blades torque should be positive”, and by analyzing the distribution of blades loading, the flow distribution rules and pump performance influenced by different splitter blades off-setting angles and inlet diameters were discovered. The disk friction loss, which consuming much energy in centrifugal pumps, was also forecasted at various operating conditions. The results were compared with that from empirical formulas, which show great accordance at the rated point, and the forecasted results at off-design points were analyzed also. Finally, the research results and the design method for the centrifugal pump with splitter blades, such as how to select splitter blade number, the off-setting angle, the inlet diameter and the deflection angle, were summarized.

Development of Design Method for Supersonic Turbine Aerofoils Near the Tip of Long Blades in Steam Turbines: Part 2 — Configuration Details and Validation

2013 ◽  
Author(s):  
Shigeki Senoo ◽  
Hideki Ono
Keyword(s):  
Shock Wave ◽  
Supersonic Flow ◽  
Method Development ◽  
Design Space ◽  
Design Method ◽  
Flow Angle ◽  
Flow Passage ◽  
Pressure Surface ◽  
Outlet Flow ◽  
Stagger Angle

Both inflow and outflow velocities near the blade tip become supersonic when the blade length exceeds a threshold limit. The aerofoil near the tip of such a long blade has four features that demand an original supersonic turbine aerofoil design: supersonic flow in the entire field, high reaction, large stagger angle, and large pitch-to-chord ratio. This paper describes design method development for the supersonic turbine aerofoil. First, the aerofoil shape is defined using a curve with continuity in the gradient of the curvature. Second, six loss generation mechanisms are clarified by turbulent flow analysis. Third, an allowable design space between the pitch-to-chord ratio, the stagger angle and the axial-chord-to-pitch ratio is clarified by formulating three geometrical constraints to accelerate supersonic flow smoothly. When there is no solution in the theoretically allowable design space because of the large pitch-to-chord ratio, methods to reduce shock wave losses are proposed. Increasing the outlet metal angle of the pressure surface by around 10 deg from the theoretical outlet flow angle reduces the loss caused by the trailing shock wave. The physical mechanism for this is as follows: the increased outlet metal angle increases the outlet flow passage area so that the overexpansion is suppressed downstream from the flow passage. Fourth, both a cusped leading edge and an upstream pressure surface which has both an angle corresponding to the inflow angle and near-zero curvature can reduce the loss caused by the leading shock wave and satisfy the unique incidence relation. Finally, the aerodynamic performance of the supersonic turbine cascade and the design method are validated by supersonic cascade wind tunnel tests.

scholarly journals Computation of Viscous Flow Inside a Double-Channel Centrifugal Pump

2014 ◽  
Vol 8 (1) ◽  
pp. 613-618
Author(s):  
Su-Lu Zheng ◽  
Xiang-Ping Wang ◽  
Rui-Hang Zheng ◽  
Ai-Ping Xia ◽  
Yi-Nian Wang ◽  
...  
Keyword(s):  
Viscous Flow ◽  
Centrifugal Pump ◽  
Design Method ◽  
Pure Water ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Solid Particles ◽  
Water Medium ◽  
Centrifugal Pumps ◽  
Double Channel

The double-channel centrifugal pumps are widely used to transport the two-phase flow including big solid particles in industry and agriculture. However, the related design theory and the design method are immature by far. In practice, the revised design method based on the pure water medium is still the main method for the solid-liquid twophase double-channel pump. Therefore, it is very necessary to deeply study the flow characteristics on the condition of the pure water medium. In this paper, in order to study the flow characteristics inside a prototype double-channel centrifugal pump in the case that the delivered medium is the pure water, the SIMPLE algorithm, RNG κ-ε turbulence model, and frozen rotor method are employed to calculate the incompressible, viscous, three-dimensional internal flow. The calculation results display the variation characteristics of the internal flow field and the external performance. The results show that the predicted pump head drops with the increasing flow rate, which manifest that the pump model is of good operation stability at the whole range of working. At the design point, a strong and large vortex remain appears at the middle section of the double-channel impeller. The computational fluids dynamic technology is competent to assess the internal viscous flow inside a double-channel centrifugal pump.

scholarly journals Effect of Blade Thickness on Internal Flow and Performance of a Plastic Centrifugal Pump

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Zhenfa Xu ◽  
Fanyu Kong ◽  
Lingfeng Tang ◽  
Mingwei Liu ◽  
Jiaqiong Wang ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Variable Thickness ◽  
Internal Flow ◽  
Constant Thickness ◽  
Element Analysis ◽  
Pump Performance ◽  
Blade Thickness ◽  
The Finite Element Analysis ◽  
Pump Head ◽  
And Performance

Blade thickness is an essential parameter of the impeller, which has significant effects on the pump performance. The plastic pump generally adopts thick blade due to low strength of plastic. The effects of blade thickness on the internal flow and performance of a plastic centrifugal pump were discussed based on the numerical methods. Two kinds of blade profile, the constant thickness blade (CTB) and the variable thickness blade (VTB), were investigated. The results indicated that, for the CTB, when the blade thickness was less than 6 mm, the pump performance did not change significantly. When the blade thickness exceeded 6 mm, the pump head and efficiency decreased rapidly. The pump head and efficiency of CTB 10 decreased by 42.2% and 30% compared with CTB 4, respectively. For the VTB, with blade thickness in a certain range (6 mm–14 mm), the pump performance changed slightly with the increased of trailing edge thickness. The minimum blade thickness of the plastic centrifugal pump should be 4 mm based on the finite element analysis. A variable thickness blade (VTB 4-8-4) with the maximum thickness located at 60% chord length was proposed to improve the pump performance, and its efficiency was 1.67% higher than that of the CTB 4 impeller.

A Design Method of Aero Fuel Centrifugal Pump with Integrated Inducer and Impeller

2014 ◽  
Vol 680 ◽  
pp. 303-306
Author(s):  
Jia Li ◽  
Hua Cong Li ◽  
Jiang Feng Fu ◽  
Shu Hong Wang
Keyword(s):  
Centrifugal Pump ◽  
Simulation Analysis ◽  
Design Method ◽  
Internal Flow ◽  
Field Performance ◽  
Simulation Method ◽  
Hybrid Network ◽  
Control Technique ◽  
Pressure Side ◽  
Flow Conditions

With the development of the aero engine control technique, aero fuel centrifugal pump with integrated inducer and impeller meet the requirements better than the divided pump. This paper established the hybrid network of the centrifugal pump which adopted multi-block topology structure and octree format, analyzed the internal flow field performance of the pump based on numerical simulation. The simulation datas compared with test datas show that under different calculation conditions, head error of the simulation data and experimental data is less than 1%, and the efficiency value of error is less than 5%. The simulation method can accurately calculate the performance of the pump. The simulation analysis shows that the asymmetry of the impeller internal pressure is appreciable under different flow conditions because of the inlet length, under other small flow conditions. The most dramatic change is the pressure in the impeller channel, and the pressure under large flow conditions is lower than that under other flow conditions. In fixed location of the pressure side, there may produce low speed flow group, the situation is the same as in the entrance to the attachment of back pressure side.

scholarly journals Influence of Channel-Diffuser Blades on Energy Performance of a Three-Stage Centrifugal Pump

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 277
Author(s):  
Wenbin Zhao ◽  
Jianbin Hu ◽  
Kai Wang
Keyword(s):  
Centrifugal Pump ◽  
Convex Surface ◽  
Internal Flow ◽  
Energy Performance ◽  
Outer Edge ◽  
Impeller Blade ◽  
Pressure Distributions ◽  
Outlet Angle ◽  
Wrap Angle ◽  
Inlet Angle

In order to improve hydraulic efficiency, influence of inlet angle, outlet angle, wrap angle, inlet shape and outer edge camber lines of channel-diffuser blades on the energy performance of a three-stage centrifugal pump were studied and the pressure distributions on the blade of the first-stage channel-diffuser were particularly analyzed. The result shows that the efficiency of the pump is maximal when the blade inlet angle is 12°. The pressure variation in the model with the inlet angle of 12° was small and the amplitude of fluctuation was also not large. When the outlet angle was 90°, the pressure distribution in the outlet of the blades that are symmetrically distributed along the center of the diffuser shell was significantly better than that with other outlet angles. The effect of the blade wrap angle of the channel-diffuser on the energy performance of the pump was relatively small. The internal flow in the diffuser with the diffusion inlet shapes was steady for both the convex surface and concave surface. The diffusion inlet of the channel-diffuser blade corresponded to the outlet region of the impeller blade, which reflected a good matching. The fluctuation amplitude and the distribution range of the models with a uniform transition were smaller than those with non-uniform transition. In order to verify the effectiveness of the research results, an experimental test was carried out on the pump. The results show that when the flow rate is 850 m3/h, the head of the pump is 138.67 m and the efficiency of pump is 69.48%.

scholarly journals Influence of Blade Profiles on Plastic Centrifugal Pump Performance

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Hui Zhang ◽  
Lingfeng Tang ◽  
Yongtao Zhao
Keyword(s):  
Centrifugal Pump ◽  
Volume Fraction ◽  
Interaction Analysis ◽  
Three Dimensional ◽  
Internal Flow ◽  
Logarithmic Spiral ◽  
Total Power ◽  
Impeller Blade ◽  
Pump Performance ◽  
Dimensional Models

To study the influence of blade profiles of the plastic centrifugal pump on pump performance, the impeller blade profiles were designed and drawn by the single arc method, double arc method, logarithmic spiral method, and B-spline curve method, respectively, with the known structural parameters.The shape and size of four profiles were drawn, and two-dimensional models and three-dimensional models of four impellers and volute were completed, respectively. The impeller models were printed by 3D printing technology, and the performance experiments of the plastic centrifugal pump were carried out. The numerical simulation of the internal flow field was performed. From the contours of the velocity and pressure, the vapor volume fraction distribution, and fluid-structure interaction analysis of impellers, the impeller drawn by the logarithmic spiral method was better than others. The optimization of the logarithmic spiral method was completed. The impeller inlet and outlet diameters (D1 and D2) and impeller inlet and outlet installation angles (β1 and β2) were taken as control variables, and the total power loss and the minimum NPSHr of the pump were taken as the objective functions. The optimization results were that D1 = 58 mm and D2 = 162 mm and β1 = 17° and β2 = 31°. The hydraulic efficiency was increased by 1.68%.

scholarly journals Effects of the outlet position of splitter blade on the flow characteristics in low-specific-speed centrifugal pump

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878952 ◽  
Author(s):  
Jinfeng Zhang ◽  
Guidong Li ◽  
Jieyun Mao ◽  
Shouqi Yuan ◽  
Yefei Qu ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Pressure Coefficient ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Suction Side ◽  
Trailing Edge ◽  
Pressure Surface ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Good Agreement

To elucidate the influences of the outlet position of splitter blades on the performance of a low-specific-speed centrifugal pump, two different splitter blade schemes were proposed: one located in the middle of the channel and the other having a deviation angle at the trailing edge of splitter blade toward the suction side of the main blade. Experiments on the model pump with different splitter blade schemes were conducted, and numerical simulations on internal flow characteristics in the impellers were studied by means of the shear stress transport k- ω turbulence model. The results suggest that there is a good agreement between the experimental and numerical results. The splitter blade schemes can effectively optimize the structure of the jet-wake pattern and improve the internal flow states in the impeller channel. In addition, the secondary flow and inlet circulation on the pressure surface of main blade, the flow separation on the suction side of splitter blade, the pressure coefficient distributions on blade surface can achieve an evident amelioration when the trailing edge of splitter blade toward the suction side of the main blade is mounted at an appropriate position.

Study of the Effect of Impeller Side Clearance on the Centrifugal Pump Performance Using CFD

2015 ◽  
Author(s):  
A. Farid Ayad ◽  
H. M. Abdalla ◽  
A. Abou El-Azm
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Reference Frame ◽  
Internal Flow ◽  
Computational Domain ◽  
Performance Parameters ◽  
Centrifugal Pumps ◽  
Empirical Formulas ◽  
Pump Performance ◽  
The Impact

Centrifugal pumps (CP) are probably among the most often used machinery in industrial facilities as well as in common practice. Compared to other types of rotating pumps, CP yield higher efficiency. In aerospace application reducing the weight of the CP impeller has the advantage of reducing mechanical stresses and enable using the CP at high number of revolution. In order to minimize the impeller weight the requirements to study and develop the CP with semi-open impeller appears. Using this type of impeller results in clearance between the impeller blades and the casing which degrade the centrifugal pump performance. The impact of this side clearance has not been deeply investigated in open literature. The present paper is devoted to reveal more details about the impact of CP side clearance on its performance. This is done by numerically investigating the influence of the variation of the CP side clearance width (0:0.2 impeller width) on the CP performance parameters at different flow rates (0:5 Liter/s). These CP performance parameters include the pump head, efficiency, slip factor, blades loads and the internal flow structure. 3-D steady numerical simulation has been carried out using commercial software, ANSYS® CFX. The computational domain consists of four zones: inlet, side gab, impeller and volute with outlet. They are defined by means of the multi-reference frame technique. The impeller is situated in the rotating reference frame, while the inlet, side gab and outlet zones are in the fixed reference frame, and they are related to each other through the “frozen rotor” interface. The meshes of four computational domains are generated separately after performing mesh sensitivity analysis. The boundary conditions are set as total pressure at inlet and the mass flow at outlet. A no-slip condition is imposed at the wall boundary defined at the blade and casing. A turbulent, incompressible flow solver has been adapted using SST k–ω turbulent model. The numerical simulation has been compared with own experimental results and a published empirical formulas to verify the numerical solution. The CFD results show an acceptable agreement with the results of the experimental work and the empirical formulas. It has been shown that the impeller side clearance have a great regression effect on the centrifugal pump performance. An explanation to the performance regression has been proposed based on the flow field feature. Performance regression could be attributed to the drop in the pressure difference between the impeller inlet and outlet. And the redistribution of the velocity inside the impeller channel and the side clearance.

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