Performance Improvement of Centrifugal Compressor Impellers by Optimizing Blade-Loading Distribution

2008 ◽  
Author(s):  
Manabu Yagi ◽  
Tadaharu Kishibe ◽  
Takanori Shibata ◽  
Hideo Nishida ◽  
Hiromi Kobayashi
Keyword(s):  
Performance Improvement ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Design Procedure ◽  
Blade Loading ◽  
Operating Range ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
Cfd Analyses ◽  
Suction Flow

The improvement of efficiency and operating range by optimizing blade-loading distribution of three-dimensional (3D) centrifugal compressor impellers is investigated using computational fluid dynamics (CFD) analyses and performance tests. The design points of suction flow coefficients investigated in the present study were 0.05 and 0.073. Two design approaches for 3D impeller were employed: a conventional method and a newly developed one. In order to achieve higher efficiency and wider operating range, the blade loading and relative velocity distribution were optimized in the new design procedure. In addition, to clarify the performance improvement of 3D impellers against current two-dimensional (2D) ones, both performance characteristics were compared. The test results showed the efficiencies of the newly designed 3D impellers were increased by about 0.5–1.5% in comparison with those of the conventional impellers, while the operating ranges of both were almost the same. Further, the efficiencies of the newly designed 3D impellers increased by about 3% in comparison with those of the 2D impellers at both design points. At the same time, the operating ranges of the former impellers were about 2.1–2.8 times as wide as those of the latter.

scholarly journals Repeated evolution of drag reduction at the air–water interface in diving kingfishers

2019 ◽  
Vol 16 (154) ◽  
pp. 20190125 ◽  
Author(s):  
K. E. Crandell ◽  
R. O. Howe ◽  
P. L. Falkingham
Keyword(s):  
Sagittal Plane ◽  
Three Dimensional ◽  
Representative Species ◽  
Evolutionary Context ◽  
Repeated Evolution ◽  
Corrected Data ◽  
Computational Fluid Dynamics Cfd ◽  
Foraging Guilds ◽  
And Performance ◽  
Cfd Analyses

Piscivorous birds have a unique suite of adaptations to forage under the water. One method aerial birds use to catch fish is the plunge dive, wherein birds dive from a height to overcome drag and buoyancy in the water. The kingfishers are a well-known clade that contains both terrestrially foraging and plunge-diving species, allowing us to test for morphological and performance differences between foraging guilds in an evolutionary context. Diving species have narrower bills in the dorsoventral and sagittal plane and longer bills (size-corrected data, n = 71 species, p < 0.01 for all). Although these differences are confounded by phylogeny (phylogenetically corrected ANOVA for dorsoventral p = 0.26 and length p = 0.14), beak width in the sagittal plane remains statistically different ( p < 0.001). We examined the effects of beak morphology on plunge performance by physically simulating dives with three-dimensional printed models of beaks coupled with an accelerometer, and through computational fluid dynamics (CFD). From physically simulated dives of bill models, diving species have lower peak decelerations, and thus enter the water more quickly, than terrestrial and mixed-foraging species (ANOVA p = 0.002), and this result remains unaffected by phylogeny (phylogenetically corrected ANOVA p = 0.05). CFD analyses confirm these trends in three representative species and indicate that the morphology between the beak and head is a key site for reducing drag in aquatic species.

Metamodel-driven data mining model to support three-dimensional design of centrifugal compressor stage

2021 ◽  
pp. 1-63
Author(s):  
Qin Ruihong ◽  
Yaping Ju ◽  
Stephen W T Spence ◽  
Chuhua Zhang
Keyword(s):  
Data Mining ◽  
Performance Improvement ◽  
Centrifugal Compressor ◽  
High Efficiency ◽  
Three Dimensional ◽  
Great Effort ◽  
Operating Range ◽  
Geometry Parameter ◽  
Mining Model ◽  
Wide Operating

Abstract The design of a centrifugal compressor with high efficiency and a wide operating range is a challenging task. A great effort has been undertaken to solve the three-dimensional design problem with the assistance of a metamodel. However, the published works lack any study that systematically performs the data mining between the performance and three-dimensional geometry variation due to two unsolved issues, i.e., lack of reliable systematic data mining model and unresolved high-dimensional data problem in the centrifugal compressor community. To tackle these issues, a systematic metamodel-driven data mining model including six general modules has been proposed and implemented to the well-known Radiver stage. In this data mining task, four specific techniques were used to go through the general to specific data mining. The results showed the performance improvement probabilities, the trade-off relationships between performance parameters, the characteristic variation of the performance, and the correlations between performance and the most sensitive two geometry parameter variation. The appropriate variation ranges for wide operating range design of the two sensitive geometry parameters were recommended and the flow mechanism behind them was clarified. The statistical results showed that over 90% of the design stages in the recommended variation ranges had a wide operating range. A design case was chosen randomly in the recommended range to verify the performance improvement via CFD simulations. The outcomes of this work are particularly relevant for the advanced design of compressors with high efficiency and a wide operating range for flexibility.

scholarly journals Investigation of Suction Flow Control on Centrifugal Compressor with Vaned Diffuser

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 583
Author(s):  
Suleyman Emre Ak ◽  
Sertac Cadirci
Keyword(s):  
Flow Control ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Vaned Diffuser ◽  
Flow Rates ◽  
Performance Improvements ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses ◽  
Suction Flow

In this study, the effect of suction flow control on a centrifugal compressor at operation and stall flow rates was investigated using computational fluid dynamics (CFD). The compressor geometry was reconstructed from available open source profile data and the CFD analyses have been performed on this geometry using the appropriate mesh. To validate the CFD results, the compressor performance line was acquired and compared with the experimental results obtained at the design rotational speed. Then, suction flow control was employed at various suction slot positions with different suction flow rates to improve the performance of the compressor at operation and stall flow rates. As a result of the suction flow control trials, 0.85% increase in pressure ratio and 0.8% increase in adiabatic efficiency were achieved while the compressor was running at operation flow rate. The performance improvements corresponding to the stall flow rate of the compressor were 2.5% increase in pressure ratio and 2% increase in adiabatic efficiency.

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

2020 ◽  
pp. 095441002096645
Author(s):  
Jie Gao ◽  
Chunde Tao ◽  
Dongchen Huo ◽  
Guojie Wang
Keyword(s):  
Performance Improvement ◽  
High Efficiency ◽  
Three Dimensional ◽  
Great Influence ◽  
Aerodynamic Characteristics ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Axial Turbine ◽  
Flow Interactions ◽  
And Performance

Marine, industrial, turboprop and turboshaft gas turbine engines use nonaxisymmetric exhaust volutes for flow diffusion and pressure recovery. These processes result in a three-dimensional complex turbulent flow in the exhaust volute. The flows in the axial turbine and nonaxisymmetric exhaust volute are closely coupled and inherently unsteady, and they have a great influence on the turbine and exhaust aerodynamic characteristics. Therefore, it is very necessary to carry out research on coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics, so as to provide reference for the high-efficiency turbine-volute designs. This paper summarizes and analyzes the recent advances in the field of coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery. This review covers the following topics that are important for turbine and volute coupled designs: (1) flow and loss characteristics of nonaxisymmetric exhaust volutes, (2) flow interactions between axial turbine and nonaxisymmetric exhaust volute, (3) improvement of turbine and volute performance within spatial limitations and (4) research methods of coupled turbine and exhaust volute aerodynamics. The emphasis is placed on the turbine-volute interactions and performance improvement. We also present our own insights regarding the current research trends and the prospects for future developments.

The Aerodynamics of Three-Dimensional Vaned Diffusers in Industrial Centrifugal Compressors

2005 ◽  
Author(s):  
Ahmed Abdelwahab
Keyword(s):  
Centrifugal Compressor ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Pressure Recovery ◽  
Navier Stokes ◽  
Spanwise Direction ◽  
Two Dimensional ◽  
Blade Loading ◽  
Recovery Capacity ◽  
Close Proximity

Vaned diffusers have been used successfully as efficient and compact dynamic pressure recovery devices in industrial centrifugal compressor stages. Typically such diffusers consist of a cascade of two-dimensional blades distributed circumferentially at close proximity to the impeller exit. In this paper three low-solidity diffuser blade geometries are numerically investigated. The first geometry employs variable stagger stacking of similar blade sections along the blade span. The second employs linearly inclined stacking to generate blade lean along the diffuser span. The third geometry employs the conventional two-dimensional low-solidity diffuser geometry with no variable stagger or lean. The variable stagger blade arrangement has the potential of better aligning the diffuser leading edges with the highly non-uniform flow leaving the impeller. Both variable stagger and linearly leaned diffuser blade arrangements, however, have the effect of redistributing the blade loading and flow streamlines in the spanwise direction leading to improved efficiency and pressure recovery capacity of the diffuser. In this paper a description of the proposed diffuser geometries is presented. The results of Three-dimensional Navier-Stokes numerical simulations of the three centrifugal compressor arrangements are discussed. Comparisons between the performance of the two and three-dimensional diffuser blade geometries are presented. The comparisons indeed show that the variable stagger and leaned diffusers present an improvement in the diffuser operating range and pressure recovery capacity over the conventional two-dimensional diffuser geometry.

Improving a one-dimensional centrifugal compressor performance prediction method

2005 ◽  
Vol 219 (8) ◽  
pp. 653-659 ◽  
Author(s):  
E Swain
Keyword(s):  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Prediction Method ◽  
Compressor Cascade ◽  
One Dimensional ◽  
Compressor Performance ◽  
Cfd Analyses

A one-dimensional centrifugal compressor performance prediction technique that has been available for some time is updated as a result of extracting the component performance from three-dimensional computational fluid dynamic (CFD) analyses. Confidence in the CFD results is provided by comparison of overall performance for one of the compressor examples. The extracted impeller characteristic is compared with the original impeller loss model, and this indicated that some improvement was desirable. The position of least impeller loss was determined using a traditional axial compressor cascade method, and suitable algebraic expressions were derived to match the CFD data. The merit of the approach lies with the relative ease that CFD component performance currently can be achieved and adjusting one-dimensional methods to agree with the CFD-derived models.

scholarly journals Semi-Inverse Design of Compressor Cascades, Including Supersonic Inflow

1990 ◽  
Author(s):  
A. Kirschner ◽  
H. Stoff
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Design Procedure ◽  
Meridional Plane ◽  
Simple Method ◽  
Blade Loading ◽  
Through Flow ◽  
Blade Element

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.

Design and Performance Analysis of a Supercritical CO2 Centrifugal Compressor With Variable Geometry

2021 ◽  
Author(s):  
Gang Fan ◽  
Kang Chen ◽  
Shaoxiong Zheng ◽  
Yang Du ◽  
Yiping Dai ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Optimization Design ◽  
High Efficiency ◽  
Superior Performance ◽  
Variable Geometry ◽  
Power Cycles ◽  
Operating Range ◽  
Stable Operating ◽  
And Performance ◽  
Geometry Method

Abstract The supercritical carbon dioxide (SCO2) Brayton cycle is one of the most promising power cycles due to its high efficiency, compactness and environmentally friendliness. The centrifugal compressor is a key component of small and medium SCO2 Brayton cycles, and its efficiency has a significant impact on the cycle efficiency. Since the required electric load of power cycles always fluctuates over the year, the SCO2 compressor will operate away from its design point and the narrow stable operating range of a compressor is always a restriction. In this paper, the variable-geometry method, which refers to the combination of a variable inlet-guide-vanes and variable diffuser vanes is proposed for the operating range extension of SCO2 compressors. A set of one-dimensional (1D) loss correlations has been found to accurately predict various losses of the SCO2 compressor components. Based on the 1D thermodynamic model, two programs with internal MATLAB codes coupled with the NIST REFPROP database have been developed for preliminary optimization design and off-design performance predictions of the variable geometry SCO2 compressor. The contributions from the variable-inlet prewhirl and variable diffuser vanes to the shifts of the surge line and choke line are discussed in this paper. The results show the variable-geometry SCO2 compressor has a superior performance at off-design conditions and a wider operating range.

Performance Characteristics of Two- and Three-Dimensional Impellers in Centrifugal Compressors

1988 ◽  
Vol 110 (1) ◽  
pp. 110-114 ◽  
Author(s):  
H. Harada
Keyword(s):  
Centrifugal Compressor ◽  
Closed Loop ◽  
Three Dimensional ◽  
Test Stand ◽  
Performance Characteristics ◽  
Working Fluid ◽  
Angle Distribution ◽  
Blade Angle ◽  
Operating Range ◽  
Overall Performance

The overall performance of two- and three-dimensional impellers of a centrifugal compressor were tested and compared. A closed-loop test stand with Freon gas as the working fluid was employed for the experiments. The inlet and outlet velocity distributions of all impellers were measured using three-hole cobra probes. As a result, it has been revealed that three-dimensional impeller in terms of efficiency, head coefficient, and operating range. Further, it has also been clarified that the impeller slip factor is affected by blade angle distribution.

An Approximate Three-Dimensional Aerodynamic Design Method for Centrifugal Impeller Blades

1990 ◽  
Vol 112 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Zhao Xiaolu ◽  
Qin Lisen
Keyword(s):  
Centrifugal Compressor ◽  
Design Method ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Design Procedure ◽  
Taylor Series Expansion ◽  
Centrifugal Impeller ◽  
Aerodynamic Design ◽  
Impeller Blade ◽  
Blade Geometry

An aerodynamic design method, which is based on the Mean Stream Surface Method (MSSM), has been developed for designing centrifugal compressor impeller blades. As a component of a CAD system for centrifugal compressor, it is convenient to use the presented method for generating impeller blade geometry, taking care of manufacturing as well as aerodynamic aspects. The design procedure starts with an S2m indirect solution. Afterward from the specified S2m surface, by the use of Taylor series expansion, the blade geometry is generated by straight-line elements to meet the manufacturing requirements. Simultaneously, the fluid dynamic quantities across the blade passage can be determined directly. In terms of these results, the designer can revise the distribution of angular momentum along the shroud and hub, which are associated with blade loading, to get satisfactory velocities along the blade surfaces in order to avoid or delay flow separation.

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