The Optimization of a Centrifugal Impeller Based on a New Multi-Objective Evolutionary Strategy

2016 ◽  
Author(s):  
Xiaojian Li ◽  
Yijia Zhao ◽  
Zhengxian Liu ◽  
Hua Chen
Keyword(s):  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
Evolutionary Strategy ◽  
Centrifugal Impeller ◽  
Nsga Ii ◽  
Multi Objective ◽  
Compressor Performance ◽  
Aero Engines ◽  
Total Pressure Ratio ◽  
Petrochemical Engineering

Centrifugal compressors with high aerodynamic performance are widely used in turbochargers, aero-engines and petrochemical engineering. The impeller is the core component and plays a key role in determining the compressor performance. This paper reports the optimisation of the aerodynamic performance of an industrial centrifugal impeller by a multi-objective evolutionary strategy. Firstly the 3-D modeling method for parameterisation of impeller’s geometry was described. Secondly the traditional NSGA-II method was modified to improve its ability and efficiency. Employed CFD code was first validated using the experimental data of an existing impeller. The optimisation was applied to the industrial centrifugal impeller through a two-step optimization process to allow for significant variations of the impeller geometry and speedy finding of the optimum. The optimisation was completed within 53 hours on a workstation with two 24-core processors (Xeon(R) E5-2670 v3 2.3GHz). The results indicated that the isentropic efficiency of the impeller increased by 5.3 percents and the total pressure ratio by 20.5 percents at design condition.

Aerodynamic Analysis and Multi-Objective Optimization Design of a High Pressure Ratio Centrifugal Impeller

2014 ◽  
Author(s):  
Zhendong Guo ◽  
Zhiming Zhou ◽  
Liming Song ◽  
Jun Li ◽  
Zhenping Feng
Keyword(s):  
Data Mining ◽  
High Pressure ◽  
Pressure Ratio ◽  
Differential Evolution Algorithm ◽  
Aerodynamic Performance ◽  
Centrifugal Impeller ◽  
Tip Leakage Flow ◽  
Pareto Solutions ◽  
Multi Objective ◽  
High Pressure Ratio

The design of high pressure ratio impellers is a challenging task. SRV2-O, a typical high pressure ratio centrifugal impeller is selected for the research. A good understanding of flow characteristics in the passage of SRV2-O is obtained by using 3D Reynolds-Averaged Navier-Stokes (RANS) solutions upon numerical validation. It confirms that tip leakage flow and shock wave boundary layer interactions produce the primary energy loss in this transonic impeller. A 3D multi-objective aerodynamic optimization and data mining method named BMOE is presented and programmed by integrating a self-adaptive multi-objective differential evolution algorithm SMODE, 3D blade parameterization method based on non-uniformed B-Spline, RANS solver technique and self-organization map (SOM) based data mining technique. Using BMOE, multi-objective aerodynamic design optimization and data mining is performed for SRV2-O. 14 Pareto solutions are obtained for maximizing isentropic efficiency and total pressure ratio of the impeller. Three typical Pareto solutions, Design A with the highest efficiency, Design B with the higher efficiency and larger pressure ratio and Design C with the maximum pressure ratio, are analyzed. Detailed analysis indicates that the aerodynamic performance of optimized designs is greatly improved. Furthermore, by SOM-based data mining on optimization results, trade-off relation between objective functions and parameter influence mechanism on impeller aerodynamic performance are visualized and explored.

scholarly journals Multi-Objective Aerodynamic Design Optimisation Method of Fuel Cell Centrifugal Impeller Using Modified NSGA-II Algorithm

2021 ◽  
Vol 11 (16) ◽  
pp. 7659
Author(s):  
Jisheng Liu ◽  
Wei Li ◽  
Manxian Liu ◽  
Ketai He ◽  
Yesong Wang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Working Conditions ◽  
Mass Flow ◽  
Pressure Ratio ◽  
Centrifugal Impeller ◽  
Aerodynamic Design ◽  
Ratio Increase ◽  
Design Optimisation ◽  
Nsga Ii ◽  
Multi Objective

This paper presents a modified NSGA-II algorithm based on the spatial density (SD) operator, combined with computer graphics-based surface parameterisation methods and computational fluid dynamics (CFD) simulations. This was done to optimise the multi-objective aerodynamic design of a centrifugal impeller for a 100-kW vehicle-mounted fuel cell and improve the multi-conditions aerodynamic performance of the centrifugal impeller of the vehicle-mounted fuel cell (FC). The optimisation objectives are to maximise the isentropic efficiency of the rated and common operating conditions. The optimisation results showed that the efficiency of rated working conditions had an increase of 1.29%, mass flow increase of 8.8%, pressure ratio increase of 0.74% and comprehensive margin increase of 6.2%. The efficiency of common working conditions had an increase of 1.2%, mass flow increase of 9.1%, pressure ratio increase of 0.24% and comprehensive margin increase of 10%. The optimisation effect is obvious under the premise of satisfying the constraints, which proves the optimisation method’s engineering effectiveness and provides technical support and methodological research for the multi-objective aerodynamic design optimisation of centrifugal impellers for vehicle-mounted FCs.

Multi-Objective Optimization Design Method for Tandem Compressor Cascade at Design and Off Design Conditions

2010 ◽  
Author(s):  
Yaping Ju ◽  
Chuhua Zhang
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
Multi Objective Optimization ◽  
Ann Model ◽  
Compressor Cascade ◽  
Control Cost ◽  
Multi Objective ◽  
Operation Conditions

Recently, there has been a renewed interest in the research of tandem compressor cascades due to the high stage pressure ratio and low control cost. Firstly, the computational fluid dynamics (CFD) method is employed to examine the particular aerodynamic performance of the tandem cascade. Then we propose an automatic multi-objective optimization design method of the tandem cascade for the superior aerodynamic performance under the multiple operation conditions. Particular efforts have been devoted to the gap geometry optimization in terms of the front and aft airfoil relative position, camber turning ratio as well as chord ratio. The multi-objective optimization algorithm comprises a refined multi-objective genetic algorithm (MOGA) and a developed artificial neural network (ANN) model which is used to fast approximate the aerodynamic performance of the tandem cascade. The results show that the tandem cascade outperforms the single cascade in terms of producing higher pressure ratio and lower losses while the operation range is rather narrow. The optimized all-better-than (ABT) tandem cascade has its design point performance significantly improved while the operation range slightly widened. We also find that a slight axial proximity and separation of the tandem airfoils are beneficial to widening the positive and negative operation range, respectively. This research is useful to the tandem compressor cascade design in minimizing the stage number of the engine compressors.

Centrifugal Compressor Blade Trimming for a Range of Flows

2001 ◽  
Author(s):  
C. Rodgers
Keyword(s):  
Centrifugal Compressor ◽  
Test Performance ◽  
Pressure Ratio ◽  
Performance Characteristics ◽  
Centrifugal Impeller ◽  
Impeller Blade ◽  
Flow Capacity ◽  
Component Test ◽  
Compressor Performance ◽  
Stage Efficiency

Centrifugal impeller blade trimming has long been used in the turbocharger industry to adapt a single impeller casting to a series of flow capacities, but surprisingly little published literature exists on the effects of trimming to compressor performance. This paper is presented as partial remedy, and describes the performance characteristics of a single stage centrifugal compressor designed and tested to cover a range of flow requirements by impeller blade and diffuser vane trimming. Stage and component test performance characteristics are presented for five trimmed flowpath contours covering a flow capacity range of approximately five to one at a DeLaval number of 0.75. The impeller tip diameter was 356mm, and the highest overall stage efficiency measured was 84.8% at an (air) pressure ratio of 1.5.

Robust Optimization Design of Single-Stage Transonic Axial Compressor Considering the Manufacturing Uncertainties

2018 ◽  
Author(s):  
Zhihui Li ◽  
Yanming Liu ◽  
Ramesh K. Agarwal
Keyword(s):  
Total Pressure ◽  
Optimization Design ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Tip Clearance ◽  
Robust Design Optimization ◽  
Compressor Performance ◽  
Overall Performance ◽  
Transonic Axial Compressor ◽  
Total Pressure Ratio

Manufacturing uncertainties always lead to significant variability in compressor performance. In this work, the tip clearance uncertainties inherent in a transonic axial compressor are quantified to determine their effect on performance. The validated tip clearance losses model in conjunction with the 3D reynolds averaged navier-stokes (RANS) solver are utilized to simulate these uncertainties and quantify their effect on the adiabatic efficiency, total pressure ratio and choked mass flow. The sensitivity analysis method is employed to figure out which parameters play the most significant roles in determining the overall performance of compressor. To propagate these uncertainty factors, the non-intrusive polynomial chaos expansion (PCE) algorithm is used in this paper and the probability distributions of compressor performance are successfully predicted. A robust design optimization has been carried out based on the combination of the genetic algorithm (GA) and the uncertainty quantification (UQ) method, leading to a robust compressor rotor design for which the overall performance is relatively insensitive to variability in tip clearance without reducing the sources of the manufacturing noise. The optimization results show that the mean value of the adiabatic rotor efficiency is improved by 1.4 points with the overall variation of that reduced by 64.1%, while the total pressure ratio is slightly improved when compared to the prototype.

Effect of Backward Sweep on Aerodynamic Performance of a 1.5-Stage Highly Loaded Axial Compressor

2020 ◽  
Author(s):  
Song Huang ◽  
Chuangxin Zhou ◽  
Chengwu Yang ◽  
Shengfeng Zhao ◽  
Mingyang Wang ◽  
...  
Keyword(s):  
Total Pressure ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Aerodynamic Performance ◽  
Blade Loading ◽  
Stall Margin ◽  
Axial Compressors ◽  
Design Speed ◽  
Total Pressure Ratio ◽  
Highly Loaded

Abstract As a degree of freedom in the three-dimensional blade design of axial compressors, the sweep technique significantly affects the aerodynamic performance of axial compressors. In this paper, the effects of backward sweep rotor configurations on the aerodynamic performance of a 1.5-stage highly loaded axial compressor at different rotational design speeds are studied by numerical simulation. The aim of this work is to improve understanding of the flow mechanism of backward sweep on the aerodynamic performance of a highly loaded axial compressor. A commercial CFD package is employed for flow simulations and analysis. The study found that at the design rotational speed, compared with baseline, backward sweep rotor configurations reduce the blade loading near the leading edge but slightly increases the blade loading near the trailing edge in the hub region. As the degree of backward sweep increases, the stall margin of the 1.5-stage axial compressor increase first and then decrease. Among different backward sweep rotor configurations, the 10% backward sweep rotor configuration has the highest stall margin, which is about 2.5% higher than that of baseline. This is due to the change of downstream stator incidence, which improves flow capacity near the hub region. At 80% rotational design speed, backward sweep rotor configurations improve stall margin and total pressure ratio of the compressor. It’s mainly due to the decreases of the rotor incidence near the middle span, which results in the decreases of separation on the suction surface. At 60% rotational design speed, detached shock disappears. Backward sweep rotor configurations deteriorate stall margin of the compressor, but increase total pressure ratio and adiabatic efficiency when the flow rate is lower than that at peak efficiency condition. Therefore, it’s necessary to consider the flow field structure of axial compressors at whole operating conditions in the design process and use the design freedom of sweep to improve the aerodynamic performance.

Suppression of secondary flows in a centrifugal impeller by optimisation design

2020 ◽  
Vol 37 (9) ◽  
pp. 3023-3044
Author(s):  
Xing Xie ◽  
Zhenlin Li ◽  
Baoshan Zhu ◽  
Hong Wang
Keyword(s):  
Control Parameter ◽  
Aerodynamic Performance ◽  
Secondary Flows ◽  
Inverse Design ◽  
Design System ◽  
Centrifugal Impeller ◽  
Cfd Analysis ◽  
Blade Loading ◽  
Content Type ◽  
Multi Objective

Purpose The purpose of this study is to suppress secondary flows and improve aerodynamic performance of a centrifugal impeller. Design/methodology/approach A multi-objective optimisation design system was described. The optimization design system was composed of a three-dimensional (3D) inverse design, multi-objective optimisation and computational fluid dynamics (CFD) analysis. First, the control parameter ΔCp for the secondary flows was derived and selected as the optimisation objective. Then, aimed at minimising ΔCp, a 3D inverse design for impellers with different blade loading distributions and blade lean angles was completed and multi-objective optimisation was conducted. Lastly, the improvement in the distribution of secondary flows and aerodynamic performance of the optimal impeller was demonstrated by CFD analysis. Findings The study derived the control parameter ΔCp for the secondary flows. ΔCp can indicate the distribution of secondary flows both near the blade pressure and suction surfaces. As ΔCp decreased, secondary flows decreased. The blade loading distribution with fore maximum blade loading at the shroud and aft maximum blade loading at the hub, coupled with a small negative blade lean angle, could help suppress secondary flows and improve aerodynamic efficiency. Originality/value A direct control method on internal flow field characteristic-secondary flows by optimisation design was proposed for a centrifugal impeller. The impeller optimisation design process saves time by avoiding substantial CFD sample calculations.

scholarly journals Centrifugal Compressor Performance Improvement through Multi Splitter Impeller

2019 ◽  
Vol 26 (2) ◽  
pp. 6-14
Author(s):  
Adil Malik ◽  
Qun Zheng ◽  
Shafiq R. Qureshi ◽  
Salman A. Ahmed ◽  
D. KB Gambo
Keyword(s):  
Performance Improvement ◽  
Centrifugal Compressor ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Suction Surface ◽  
Pressure Surface ◽  
Percent Increase ◽  
Compressor Performance ◽  
Overall Performance ◽  
Total Pressure Ratio

Abstract In the paper, a back swept impeller of centrifugal compressor is experimentally studied and numerically validated and modified to increase its pressure ratio and improve efficiency, as well as to analyse the effect of splitter blade location between two main blades. The back swept multi splitter blade impeller was designed with a big splitter positioned close to the main blade suction surface and a smaller splitter close to the pressure surface. Adding this multi splitter improves the overall performance of the modified impeller due to less intensive flow separation and smaller pressure loss. In particular, the total pressure ratio was observed to increase from 4.1 to 4.4, with one percent increase in efficiency.

3D CFD Compressor Map Computation Process Accounting for Geometry Changes due to Off-Design Operation Loads

2014 ◽  
Author(s):  
Christian Janke ◽  
Kai Karger ◽  
Lilia Gaun ◽  
Dieter Bestle ◽  
André Huppertz
Keyword(s):  
Design Process ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Quality Performance ◽  
Computation Process ◽  
Compressor Map ◽  
Aero Engines ◽  
Total Pressure Ratio

Compressor maps of aero engines show the relation between corrected inlet mass flow and total pressure ratio for various engine speeds. Different speed lines represent different operating conditions of the compressor, where especially operating bounds like surge and choke are important for the design process. Typically, 3D CFD compressor maps are computed with the so called hot geometry given for the aerodynamic design point. However, in reality airfoil shapes will change for different engine speeds and gas loads resulting in twisted airfoils and changed tip clearances. Thus, using the nominal hot geometry for the whole compressor map is not fully correct. In order to obtain higher quality performance maps these effects need to be considered. The paper shows a process for computing compressor maps with 3D CFD, where strucural deformations of the blade due to varying speeds and gas loads are taken into account by blade morphing. This process is applied to a 1.5-stage compressor showcase.

scholarly journals Numerical study of probe parameters on performance of a transonic axial compressor

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245711
Author(s):  
Asad Islam ◽  
Hongwei Ma
Keyword(s):  
Total Pressure ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Aerodynamic Performance ◽  
Ansys Cfx ◽  
Transonic Axial Compressor ◽  
Total Pressure Ratio ◽  
Flow Case ◽  
Probe Block

The paper shows the effect of the probe on the performance of a transonic axial speed compressor. The unobstructed flow case with the experimental data was validated and used as a guide for all subsequent study cases. The aerodynamic performance for different probe parameters were calculated numerically using ANSYS-CFX. This covered the results on compressor output from changing probe axial positions, the radial immersion depths, the size of the probe, and the total number of probes. The findings were evaluated in relation to the total pressure ratio, performance, margin of deflation and stability. The velocity part distributions further showed that the probe block and raises the flow Mach value, which is the explanation why the compressor rotor’s total pressure ratio is lost. In fact, the parameters of the sample will significantly influence the calculation outcomes and affect the standard margin. The range of stability was also affected, which changes the performance trend from the choke to the stall. Consequently, the collection of correct probe parameters with fewer impact on compressor output is addressed.

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