scholarly journals Matching Optimization of a Mixed Flow Pump Impeller and Diffuser Based on the Inverse Design Method

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 260
Author(s):  
Mengcheng Wang ◽  
Yanjun Li ◽  
Jianping Yuan ◽  
Fareed Konadu Osman

When considering the interaction between the impeller and diffuser, it is necessary to provide logical and systematic guidance for their matching optimization. In this study, the goal was to develop a comprehensive matching optimization strategy to optimize the impeller and diffuser of a mixed flow pump. Some useful tools and methods, such as the inverse design method, computational fluid dynamics (CFD), design of experiment, surrogate model, and optimization algorithm, were used. The matching optimization process was divided into two steps. In the first step, only the impeller was optimized. Thereafter, CFD analysis was performed on the optimized impeller to get the circulation and flow field distribution at the outlet of the impeller. In the second step of optimization, the flow field and circulation distribution at the inlet of the diffuser were set to be the same as the optimized impeller outlet. The results show that the matching optimization strategy proposed in this study is effective and can overcome the shortcomings of single-component optimization, thereby further improving the overall optimization effect. Compared with the baseline model, the pump efficiency of the optimized model at 1.2Qdes, 1.0Qdes, and 0.8Qdes is increased by 6.47%, 3.68%, and 0.82%, respectively.

2021 ◽  
Vol 11 (2) ◽  
pp. 507
Author(s):  
Mengcheng Wang ◽  
Yanjun Li ◽  
Jianping Yuan ◽  
Fareed Konadu Osman

The spanwise distribution of impeller exit circulation (SDIEC) has an important influence on the performance of the impeller. To quantitatively study the influence of SDIEC on optimization results, a comprehensive optimization system composed of the computational fluid dynamics, inverse design method, design of experiment, surrogate model, and optimization algorithm was used to optimize a mixed flow pump impeller in two different cases. In the first case, the influence of SDIEC was ignored, while in the second case, the influence of SDIEC was considered. The result shows that the optimization upper limit can be further improved when the influence of SDIEC is considered in the optimization process. The pump efficiency of the preferred optimized impeller F1 obtained in the first case at 1.2Qdes, 1.0Qdes, and 0.8Qdes are increased by 6.48%, 2.41%, and 0.06%, respectively, over the baseline model. Moreover, the pump efficiency of the preferred optimized impeller S2 obtained in the second case further increased by 0.76%, 1.24%, and 1.21%, respectively, over impeller F1. Furthermore, the influence of SDIEC on the performance of the mixed flow pump is clarified by a comparative analysis of the internal flow field.


Author(s):  
M. Zangeneh ◽  
A. Goto ◽  
T. Takemura

This paper describes the design of the blade geometry of a medium specific speed mixed flow pump impeller by using a 3D inverse design method in which the blade circulation (or rVθ) is specified. The design objective being the reduction of impeller exit flow non-uniformity by reducing the secondary flows on the blade suction surface. The paper describes in detail the aerodynamic critria used for the suppression of secondary flows with reference to the loading distribution and blade stacking condition used in the design. The flow through the designed impeller is computed by Dawes viscous code, which indicates that the secondary flows are well suppressed on the suction surface. Comparison between the predicted exit flow field of the inverse designed impeller and a corresponding conventional impeller indicates that the suppression of secondary flows has resulted in substantial improvement in the exit flow field. Experimental comparison of the flow fields inside and at exit from the conventional and the inverse designed impeller is made in part 2 of the paper.


1996 ◽  
Vol 118 (3) ◽  
pp. 536-543 ◽  
Author(s):  
M. Zangeneh ◽  
A. Goto ◽  
T. Takemura

This paper describes the design of the blade geometry of a medium specific speed mixed flow pump impeller by using a three-dimensional inverse design method in which the blade circulation (or rVθ) is specified. The design objective is the reduction of impeller exit flow nonuniformity by reducing the secondary flows on the blade suction surface. The paper describes in detail the aerodynamic criteria used for the suppression of secondary flows with reference to the loading distribution and blade stacking condition used in the design. The flow through the designed impeller is computed by Dawes’ viscous code, which indicates that the secondary flows are well suppressed on the suction surface. Comparison between the predicted exit flow field of the inverse designed impeller and a corresponding conventional impeller indicates that the suppression of secondary flows has resulted in substantial improvement in the exit flow field. Experimental comparison of the flow fields inside and at exit from the conventional and the inverse designed impeller is made in Part 2 of the paper.


1996 ◽  
Vol 118 (3) ◽  
pp. 544-551 ◽  
Author(s):  
A. Goto ◽  
T. Takemura ◽  
M. Zangeneh

In Part 1 of this paper, a mixed-flow pump impeller was designed by a fully three-dimensional inverse design method, aimed at suppressing the secondary flows on the blade suction surface. In this part, the internal flow fields of the impeller are investigated experimentally, using flow visualization and phase-locked measurements of the impeller exit flow, in order to validate the effects of secondary flow suppression. The flow fields are compared with those of a conventional impeller, and it is confirmed that the secondary flows on the blade suction surface are well suppressed and the uniformity of the exit flow fields is improved substantially, in both circumferential and spanwise directions. The effects of tip clearance and the number of blades for the inverse designed impeller are also investigated experimentally and numerically.


Author(s):  
A. Goto ◽  
T. Takemura ◽  
M. Zangeneh

In Part I of this paper, a mixed-flow pump impeller was designed by a fully three-dimensional inverse design method, aimed at suppressing the secondary flows on the blade suction surface. In this part, the internal flow fields of the impeller are investigated experimentally, using flow visualization and phase-locked measurements of the impeller exit flow, in order to validate the effects of secondary flow suppression. The flow fields are compared with those of a conventional impeller, and it is confirmed that the secondary flows on the blade suction surface are well suppressed and the uniformity of the exit flow fields is improved substantially, in both circumferential and spanwise directions. The effects of tip clearance and the number of blades for the inverse designed impeller are also investigated experimentally and numerically.


Author(s):  
Xiao Pei Tian ◽  
Peng Shan

The through-flow inverse design method based on the streamline curvature approach is nowadays a widely used quasi-3-dimensional blades design method for radial and mixed flow turbomachines. The main limitation of this method is using the flow field on the mean stream surface S2,m to approximate the actual 3-dimensional flow field. Without an effective description of the periodic flow, it is impossible for this method to realize exactly the prescribed circumferentially averaged swirl rVθ. Is there any way to develop this classical through-flow inverse method to a 3-dimensional one conveniently? The answer is yes. A new compressible 3-dimensional inverse design method for radial and mixed flow turbomachines is presented in this paper. This new 3-dimensional inverse method provides a convenient and effective way to obtain the periodic flow field for the streamline curvature through-flow inverse method. Meanwhile, compared with another type of similar 3-dimensional inverse method firstly described by Tan etc. based on Stokes stream functions and Monge potential functions from the Clebsch formulation to calculate the circumferentially averaged flow and the periodic flow respectively, this new method has its own advantages. In order to assess the usefulness of the new method, four centrifugal impellers are designed under the same design specifications by four different inverse methods respectively. They are two quasi-3-dimensional streamline curvature through-flow inverse methods without and with a slip factor model, a 3-dimensional approximated inverse approach based on stream functions and Monge potential functions and the 3-dimensional inverse method presented here. The performances of the four impellers yielding from a RANS commercial solver are compared. The capabilities of the four methods to realize the target circumferentially averaged swirl are also studied.


Author(s):  
Kosuke Ashihara ◽  
Akira Goto

An optimization approach for improving turbomachinery performance was proposed based on a three-dimensional inverse design method, a Computational Fluid Dynamics (CDF) and optimization algorithm. By combining the three-dimensional inverse design method and CFD predictions, the blade loading parameters which is the major inputs for the three-dimensional inverse design method were treated as design variables and the impeller performance predicted by CFD was treated as an objective function of the optimization problem. Firstly, to clarify the effects of optimization algorithm, mixed-flow pump impellers (Ns400), with a specific speed of 400 (m3/min,m,min−1) or 0.155 (non-dimensional), were optimized to improve the impeller efficiency by using several optimization algorithm. From these results, it was confirmed that turbomachinery optimization using the three-dimensional inverse design method is a multi-peak problem and it is essential to use exploratory techniques such as Simulated Annealing. Then, a mixed-flow pump impeller (Ns1350), with a specific speed of 1350 (m3/min,m,min−1) or 0.523 (non-dimensional), was optimized to improve the impeller efficiency with constraints for suction performance by Simulated Annealing. Reasonably high efficiency and high suction performance were confirmed by comparing the CFD results with those for the previous design which employed manual optimization.


Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 905 ◽  
Author(s):  
Mengcheng Wang ◽  
Yanjun Li ◽  
Jianpin Yuan ◽  
Fan Meng ◽  
Desmond Appiah ◽  
...  

The spanwise distribution of impeller exit circulation (SDIEC) has a significant effect on the impeller performance, therefore, there is a need for its consideration in the optimization design of mixed-flow pumps. In this study, a combination optimization system, including a 3D inverse design method (IDM), computational fluid dynamics (CFD), Latin hypercube sampling (LHS) method, response surface model (RSM), and non-dominated sorting genetic algorithm (NSGA-Ⅱ) was used to improve the performance of the mixed-flow pump after considering the effect of SDIEC on the performance of the impeller. The CFD results confirm the accuracy and credibility of the optimization results because of the good agreement the CFD results established with the experimental measurements. Compared with the original impeller, the pump efficiency of the preferred impeller at 0.8Qdes, 1.0Qdes, and 1.2Qdes improved by 0.63%, 3.39%, and 3.77% respectively. The low-pressure region on the blade surface reduced by 96.92% while the pump head difference was less than 1.84% at the design point. In addition, a comparison of the flow field of the preferred impeller and the original impeller revealed the effect of SDIEC on mixed-flow pump performance improvement and flow mechanism.


Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 46 ◽  
Author(s):  
Di Zhu ◽  
Ran Tao ◽  
Ruofu Xiao

Mixed-flow pumps compromise large flow rate and high head in fluid transferring. Long-axis mixed-flow pumps with radial–axial “spacing” guide vanes are usually installed deeply under water and suffer strong cavitation due to strong environmental pressure drops. In this case, a strategy combining the Diffusion-Angle Integral Design method, the Genetic Algorithm, and the Computational Fluid Dynamics method was used for optimizing the mixed-flow pump impeller. The Diffusion-Angle Integral Design method was used to parameterize the leading-edge geometry. The Genetic Algorithm was used to search for the optimal sample. The Computational Fluid Dynamics method was used for predicting the cavitation performance and head–efficiency performance of all the samples. The optimization designs quickly converged and got an optimal sample. This had an increased value for the minimum pressure coefficient, especially under off-design conditions. The sudden pressure drop around the leading-edge was weakened. The cavitation performance within the 0.5–1.2 Qd flow rate range, especially within the 0.62–0.78 Qd and 1.08–1.20 Qd ranges, was improved. The head and hydraulic efficiency was numerically checked without obvious change. This provided a good reference for optimizing the cavitation or other performances of bladed pumps.


Sign in / Sign up

Export Citation Format

Share Document