Performance optimization of liquid ring pumps based on Gappy POD surrogate model

2021 ◽  
Author(s):  
Guangqiang Guo ◽  
Renhui Zhang ◽  
Junhu Yang ◽  
Jingyi Wang
Keyword(s):  
Flow Field ◽  
Performance Optimization ◽  
Surrogate Model ◽  
Cfd Simulation ◽  
Design Parameters ◽  
Gradient Vector ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Blade Shape ◽  
Liquid Ring

To solve the problems of high calculation cost and difficult optimization caused by the complex gas–liquid two-phase flow in liquid ring pumps, an optimization method of a liquid ring pump impeller based on the proper orthogonal decomposition (POD) surrogate model was proposed. The impeller blade shape was parameterized by using the quartic Bezier curve. The sample was obtained from the uniform experimental design of blade shape design parameters. The POD surrogate model was constructed by the parameters of sample blade shape and its corresponding flow field data, which was used instead of CFD numerical simulation to predict the flow field variables under the perturbations of blade design parameters in the optimization process. And then, the gradient vector of the objective function to design variables was predicted quickly and accurately. The blade shape was updated continuously along the negative direction of the gradient vector, and then, the optimal design of the impeller was acquired. The calculation case results show that the relative error between the pressure field in the impeller predicted by the POD method and that of CFD simulation is less than 5%, and the calculation cost is only 1/8460 of CFD simulation. Compared with the original model, the flow field distribution in the optimized model is significantly improved, and the efficiency is promoted by 3.8%.

Optimization of Supersonic Axial Turbine Blades Based on Surrogate Models

2020 ◽  
Author(s):  
Markus Waesker ◽  
Bjoern Buelten ◽  
Norman Kienzle ◽  
Christian Doetsch
Keyword(s):  
Reynolds Number ◽  
Turbine Blade ◽  
Surrogate Model ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Energy System ◽  
Design Parameters ◽  
Blade Design ◽  
Axial Turbine ◽  
Velocity Coefficient

Abstract Due to the transition of the energy system to more decentralized sector-coupled technologies, the demand on small, highly efficient and compact turbines is steadily growing. Therefore, supersonic impulse turbines have been subject of academic research for many years because of their compact and low-cost conditions. However, specific loss models for this type of turbine are still missing. In this paper, a CFD-simulation-based surrogate model for the velocity coefficient, unique incidence as well as outflow deviation of the blade, is introduced. This surrogate model forms the basis for an exemplary efficiency optimization of the “Colclough cascade”. In a first step, an automatic and robust blade design methodology for constant-channel blades based on the supersonic turbine blade design of Stratford and Sansome is shown. The blade flow is fully described by seven geometrical and three aerodynamic design parameters. After that, an automated numerical flow simulation (CFD) workflow for supersonic turbine blades is developed. The validation of the CFD setup with a published supersonic axial turbine blade (Colclough design) shows a high consistency in the shock waves, separation zones and boundary layers as well as velocity coefficients. A design of experiments (DOE) with latin hypercube sampling and 1300 sample points is calculated. This CFD data forms the basis for a highly accurate surrogate model of supersonic turbine blade flow suitable for Mach numbers between 1.1 and 1.6. The throat-based Reynolds number is varied between 1*104 and 4*105. Additionally, an optimization is introduced, based on the surrogate model for the Reynolds number and Mach number of Colclough and no degree of reaction (equal inlet and outlet static pressure). The velocity coefficient is improved by up to 3 %.

scholarly journals Multi Effect Evaporator Design Calculation for Brown Sugar Production using Computational Fluid Dynamics

2020 ◽  
Vol 9 (3S) ◽  
pp. 87-90
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Velocity ◽  
Performance Optimization ◽  
Cfd Simulation ◽  
Design Parameters ◽  
Design Calculation ◽  
Sugar Production ◽  
Brown Sugar ◽  
Process Stage

The industrial brown sugar production process is commonly started from grinding, filtering, first heating, sulfuric acid addition, decantation, and evaporation. Evaporation process is essential process stage in the production of brown sugar. The use of Multiple Effects Evaporator (MEE) has been becoming more common and plays an important role in the food industry, especially for producing high quality agricultural products. Therefore, several design parameters of MEE should be carefully considered such as pressure, temperature, and flow velocity. This study discusses the semi-iterative design of triple effect of feed forward system MEE for industrial-scale and simulation using Computational Fluid Dynamics (CFD). This study successfully determine the optimum value for the MEE parameters in the manufacture of brown sugar and also compared with Ms.Excel-Solver simulation. The CFD simulation indicates an accurate design process that can be employed to determine the effect of pressure, temperature, and flow velocity for MEE performance optimization.

scholarly journals CFD simulation on centrifugal pump impeller with splitter blades

2020 ◽  
Vol 24 (1) ◽  
pp. 3-7 ◽  
Author(s):  
Henrique M. P. Rosa ◽  
Bruno S. Emerick
Keyword(s):  
Centrifugal Pump ◽  
Cfd Simulation ◽  
Computational Simulations ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Flow Rates ◽  
Computational Fluids Dynamics ◽  
Ansys Cfx ◽  
Computational Fluids ◽  
Centrifugal Pump Impeller

ABSTRACT The present paper aims to present the analysis and comparison of results of computational simulations using Computational Fluids Dynamics (CFD) in impellers of centrifugal pump. Three impellers were simulated: 1) original impeller, 2) original impeller with splitter blades at outlet; 3) original impeller with splitter blades at inlet. The splitters occupied 30% of the length of the main blades. They were simulated using the ANSYS-CFX software system in 1500 rpm rotational speed and at different flow rates. The turbulence model assumed was the Shear Stress Transport (SST). The results were used to build impeller blade head curves, besides the presentation of pressure distribution and streamline behaviour inside the impeller. It was verified that the insertion of the splitter blades reduced the impeller blade head, mainly the impeller with outlet splitter, whose reduction was more intense.

The Unsteady Pressure Field in a High Specific Speed Centrifugal Pump Impeller—Part II: Transient Hysteresis in the Characteristic

1999 ◽  
Vol 121 (3) ◽  
pp. 627-632 ◽  
Author(s):  
Kevin A. Kaupert ◽  
Thomas Staubli
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Pressure Fluctuations ◽  
Rate Of Change ◽  
Nonlinear Dependence ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Pump Operation ◽  
Stationary Frame ◽  
Specific Speed

Hysteresis in a pump characteristic results from instability phenomena involving complex three dimensional flow with recirculation. The unsteady flow field on the top and bottom branches of a hysteresis loop in a high specific speed (ωs = 1.7) centrifugal pump characteristic was experimentally evaluated. A hypothesis for recirculation zones and prerotation as power dissipaters is proposed for explaining the discrepancy in the pressure and shaft power hysteresis. The experimental investigation was performed in both the rotating and stationary frame. In the rotating frame 25 miniature pressure transducers mounted in an impeller blade passage were sampled with a telemetry system. In the stationary frame a fast response probe was implemented. The changing impeller flow field manifested itself between the two branches of the hysteresis with increasing stochastic pressure fluctuations. Using this information the position, size, and strength of the impeller recirculation was quantitatively determined. Theoretically the rate of change of useful hydraulic power in the hysteresis regime during transient pump operation was found to be a function of throttling rate. Quasi-steady behavior existed for slow throttling, |dφ/dt| < 0.005 s−1. A second-order nonlinear dependence on the throttle rate was determined for the change of useful flow power during the commencement/cessation of the impeller recirculation.

scholarly journals Optimal Design of a Novel ‘S-shape’ Impeller Blade for a Microbubble Pump

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1793 ◽  
Author(s):  
Seok-Yun Jeon ◽  
Joon-Yong Yoon ◽  
Choon-Man Jang
Keyword(s):  
Optimal Design ◽  
Flow Field ◽  
Three Dimensional ◽  
Maximum Error ◽  
Optimization Method ◽  
Geometric Constraints ◽  
Pump Efficiency ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Blade Thickness

The newly designed impeller blade, a so-called novel ‘S-shape’ blade, used for microbubble pumps has been introduced to enhance pump performance. Unlike a conventional blade having separated blades, like cantilever-shape blades, the newly designed impeller has a continuous blade, thus having a relatively robust structure as compared to a conventional impeller. The optimal blade design of the ‘S-shape’ blade has been demonstrated to obtain a higher pump efficiency. To analyze the three-dimensional flow field inside the pump by numerical simulation, a general analysis code, ANSYS CFX, is employed in the present work. The computed pump efficiency has a maximum error of 4 percent compared to the experimental data. The optimal design of the pump impeller blade is based on geometric constraints considering blade manufacturing, and uses three design variables: the number of blades, the blade thickness and the radius of the blade rib. The response surface method, a global optimization method, is employed to optimize the pump impeller blade. Throughout the blade optimization of the ‘S-shape’ blade, it is found that the chief influence on the pump efficiency is the number of the impeller blades. Pump efficiency, an object function, is increased by up to 35.3 percent, which corresponds to a 3.7 percent increase compared to the reference one. It is no use to say that the ‘S-shape’ blade having a continuously connected blade has more rigid characteristics. The larger pressure increases of the optimized pump along with the volute casing wall is observed from the middle position of the rotational direction, which comes from the increase of momentum energy due to larger circulating flow inside each blade passage as compared to the reference one. The detailed flow field inside the pump blades is also analyzed and compared.

Adaptive POD surrogate model method for centrifugal pump impeller flow field reconstruction based on clustering algorithm

2020 ◽  
pp. 2150126
Author(s):  
Xuebing Chen ◽  
Renhui Zhang ◽  
Lijie Jiang ◽  
Weifeng Yang
Keyword(s):  
Flow Field ◽  
Surrogate Model ◽  
Clustering Algorithm ◽  
Orthogonal Basis ◽  
Pump Impeller ◽  
Fixed Sample ◽  
Wrap Angle ◽  
Flow Field Reconstruction ◽  
Proper Orthogonal ◽  
Centrifugal Pump Impeller

To reduce the calculation cost and improve the accuracy of flow field prediction, an adaptive proper orthogonal decomposition (APOD) surrogate model based on K-means clustering algorithm was proposed to reconstruct the flow field of impeller. The experiment samples were designed by introducing the perturbation of the blade control parameters such as blade wrap angle and blade angle of outlet. K-means clustering algorithm was used to classify the sample blade shapes, and find out the cluster of the objective blade. The snapshot set, which consisted of the blade shape and the flow field data of impeller, can be described as a linear combination of orthogonal basis by POD method. The radial basis function (RBF) was used to fit the orthogonal basis coefficients of the objective blade, and then the flow field of objective impeller was reconstructed. The traditional fixed sample POD (FPOD) method and the proposed APOD method were used to reconstruct the flow field in impeller, respectively, and the prediction results of the two methods were compared and analyzed. The results show that the proposed APOD method could quickly and accurately reconstruct the objective flow field. The flow field prediction accuracy of the APOD method is significantly higher than the FPOD method, and the calculation time for the flow field prediction is less than 1/360 of the CFD.

Flow Analysis in a Pump Diffuser—Part 1: LDA and PTV Measurements of the Unsteady Flow

1997 ◽  
Vol 119 (4) ◽  
pp. 968-977 ◽  
Author(s):  
K. Eisele ◽  
Z. Zhang ◽  
M. V. Casey ◽  
J. Gu¨lich ◽  
A. Schachenmann
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Laser Doppler Anemometry ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Vaned Diffuser ◽  
Dimensional Flow ◽  
Flow Features

This paper describes experimental research aimed at improving our understanding of the complex unsteady three-dimensional flow field associated with the interaction between a pump impeller and its vaned diffuser. The paper provides the results of experiments carried out using Laser Particle Tracking Velocimetry (LPTV) and Laser Doppler Anemometry (LDA), in which time-resolved details of the unsteady flow field in a vaned diffuser of a medium specific speed pump have been obtained as a function of the local position of the pump impeller blades. Detailed flow field measurements have been carried out at several measurement positions in the diffuser and at a number of operating points along the pump characteristic. The measurement results have been analyzed to elucidate some interesting flow features observed in this typical pump diffuser. These include three-dimensional flow at the impeller outlet, flow separation in the diffuser channel, unsteady recirculation of the flow from the diffuser into the impeller, the passage of vorticity in the impeller blade wakes through the diffuser, and periodic unsteadiness and turbulence in the diffuser flow channel. The relevance of these flow features to the stability of the pump characteristic is discussed.

Multi-objective optimization of the cascade parameters of a torque converter based on CFD and a genetic algorithm

2021 ◽  
pp. 095440702098055
Author(s):  
Zilin Ran ◽  
Wenxing Ma ◽  
Chunbao Liu ◽  
Jing Li
Keyword(s):  
Genetic Algorithm ◽  
Flow Field ◽  
Surrogate Model ◽  
High Efficiency ◽  
Cfd Simulation ◽  
Pareto Frontier ◽  
Torque Converter ◽  
Solution Set ◽  
Multi Objective Optimization ◽  
Multi Objective

It is hard to simultaneously improve the peak efficiency (η *) and the width of the high-efficiency region ( Gη) for a hydrodynamic torque converter. A combination of comprehensive CFD simulation and multi-objective optimization was pretested. The elaborate CFD simulation calculation included a reasonable mesh layout, a robust algorithm and a correct turbulence model, whose results were also experimentally verified. In our study, the Kriging surrogate model was first used to construct a nonlinear relationship between the inlet and outlet angle and the economic performance index of the hydrodynamic torque converter. To ensure that the accuracy of the surrogate model meet the requirements, we also used 10 sets of sample points to verify the accuracy of our surrogate model. The accuracy is found to meet the requirements, which shows that the accuracy of the constructed surrogate model is relatively high. We choose to apply the second-generation non-dominant sorting genetic algorithm (NSGA-II) to solve our problem. After solving the Pareto frontier solution set, we obtain a set of global optimal solutions on the Pareto frontier solution set. The optimization results show that the η * is increased by 2.49% and that the Gη is increased by 14.23%. We extracted the flow field structure near the turbine region, characterized the difference between original and optimal model from the flow field perspective, and demonstrated the accuracy of our optimization results. Finally, we used CFD to verify our optimization results, further illustrating the accuracy of the optimization results prediction. Literature research indicates that a large amount of experiments to optimize the η * and the Gη of the hydrodynamic torque converter will bring huge trial cost and time cost. We conclude from our research that the proposed calculation method can solve such problems well.

scholarly journals Squirrel-Cage Fan System Optimization and Flow Field Prediction Using Parallel Filling Criterion and Surrogate Model

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1620
Author(s):  
Qianhao Xiao ◽  
Xuna Shi ◽  
Linghui Wu ◽  
Jun Wang ◽  
Yanyan Ding ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Surrogate Model ◽  
Volume Flow Rate ◽  
System Optimization ◽  
Volume Flow ◽  
Design Parameters ◽  
Maximum Volume ◽  
Squirrel Cage ◽  
Optimal Sample

In this study, the blade shape of the squirrel-cage fan system inside the range hood was optimized using the surrogate model to improve the maximum volume flow rate. The influence of computational fluid dynamics (CFD) noise was concerned. The regression Kriging model (RKM) was used as a surrogate model to reflect the relationship between the design parameters of the blade and the volume flow rate. The parallel filling criterion after re-interpolation was used to improve the optimization efficiency further and ensure global optimization. Through experimental verification, we found that the relative error between the volume flow rate of the optimal sample of RKM and the experiment was only 0.4%. Compared with the prototype, the maximum volume flow rate of the optimal sample of RKM was increased by 2.9%, and the efficiency under the corresponding working conditions was increased by 2%. RKM was used to predict the velocity field of the volute and impeller exit section to explore the feasibility of the RKM in the flow field prediction. Research shows that the RKM cannot accurately predict the velocity of each grid on the cross-section. Still, it can accurately predict the changing trend of the velocity.

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