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

1990 ◽  
Vol 112 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Zhao Xiaolu ◽  
Qin Lisen

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.

1989 ◽  
Author(s):  
Zhao Xiaolu ◽  
Qin Lisen

An aerodynamic design method, which based on the Mean Stream Surface Method (MSSM), has been developed in designing the 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. Afterwards from the specified S2m surface, by the use of Taylor series expansion, the blade geometry is generated by straight-line elements to meet the requirement of manufacture. 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.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Matteo Checcucci ◽  
Federica Sazzini ◽  
Michele Marconcini ◽  
Andrea Arnone ◽  
Mario Coneri ◽  
...  

This work provides a detailed description of the fluid dynamic design of a low specific-speed industrial pump centrifugal impeller. The main goal is to guarantee a certain value of the specific-speed number at the design flow rate, while satisfying geometrical constraints and industrial feasibility. The design procedure relies on a modern optimization technique such as an Artificial-Neural-Network-based approach (ANN). The impeller geometry is parameterized in order to allow geometrical variations over a large design space. The computational framework suitable for pump optimization is based on a fully viscous three-dimensional numerical solver, used for the impeller analysis. The performance prediction of the pump has been obtained by coupling the CFD analysis with a 1D correlation tool, which accounts for the losses due to the other components not included in the CFD domain. Due to both manufacturing and geometrical constraints, two different optimized impellers with 3 and 5 blades have been developed, with the performance required in terms of efficiency and suction capability. The predicted performance of both configurations were compared with the measured head and efficiency characteristics.


1984 ◽  
Vol 106 (2) ◽  
pp. 482-488 ◽  
Author(s):  
H. Krain

A computer-aided design method (CAD) has been developed for radially ending and backswept centrifugal compressor impellers. The geometrical concept introduced for generating the impeller geometry takes care of numerical, manufacturing, as well as aerodynamic aspects. The fluid dynamic calculation method applied is based on a quasi-three-dimensional approach coupled with a boundary layer calculation method. Detailed quantitative comparisons between theoretical data and laser measurements taken within a radially ending impeller revealed predominantly good agreement. Backswept impellers of different size and shape have been designed by the approach presented.


Author(s):  
Kaito Manabe ◽  
Sasuga Ito ◽  
Masato Furukawa ◽  
Kazutoyo Yamada ◽  
Nobuhito Oka ◽  
...  

Abstract The present optimum design method has been advanced for simultaneous optimization of impeller blade loading distribution and meridional geometry. This is based on an aerodynamic design method and a genetic algorithm. The aerodynamic design method consists of two parts: a meridional viscous flow analysis and a two-dimensional inverse blade design procedure. In the meridional viscous flow analysis, an axisymmetric viscous flow is numerically analyzed on a two-dimensional grid to determine the flow distribution around the impeller and diffuser. Effects of blades onto the axisymmetric flow field are considered by a blade force modeling. In the inverse blade design procedure, 3-D impeller geometry can be obtained from the result of meridional viscous flow analysis and the predetermined blade loading distribution. In the optimization procedure, the total pressure ratio and adiabatic efficiency obtained from the meridional viscous flow analysis are employed as objective functions. As a constraint of the optimization, mass flux distribution at the impeller trailing edge is introduced in the evaluation procedure, in order to suppress the boundary layer development near the shroud, especially under low flow rate condition. Total performances and three-dimensional flow fields of centrifugal compressors have been analyzed by 3D-RANS simulations to certify effectiveness of the present design method. The 3D-RANS simulations and the flow visualization have been applied to a conventional centrifugal compressor and optimized design cases. From the analysis results, the performance enhancement of optimized designs is confirmed under low flow rate condition including design point. In addition to that, it is revealed that the constraint works effectively on the performance improvement. As a result, construction of the simultaneous optimization using the aerodynamic design method and the genetic algorithm is successfully achieved.


2004 ◽  
Vol 126 (1) ◽  
pp. 73-81 ◽  
Author(s):  
M. Zangeneh ◽  
M. Schleer ◽  
F. Pløger ◽  
S. S. Hong ◽  
C. Roduner ◽  
...  

In this paper the three-dimensional inverse design code TURBOdesign-1 is applied to the design of the blade geometry of a centrifugal compressor impeller with splitter blades. In the design of conventional impellers the splitter blades normally have the same geometry as the full blades and are placed at mid-pitch location between the two full blades, which can usually result in a mismatch between the flow angle and blade angles at the splitter leading edge. In the inverse design method the splitter and full blade geometry is computed independently for a specified distribution of blade loading on the splitter and full blades. In this paper the basic design methodology is outlined and then the flow in the conventional and inverse designed impeller is compared in detail by using computational fluid dynamics (CFD) code TASCflow. The CFD results confirm that the inverse design impeller has a more uniform exit flow, better control of tip leakage flow and higher efficiency than the conventional impeller. The results also show that the shape of the trailing edge geometry has a very appreciable effect on the impeller Euler head and this must be accurately modeled in all CFD computations to ensure closer match between CFD and experimental results. Detailed measurements are presented in part II of the paper.


Author(s):  
Jian Wang ◽  
Suping Wen ◽  
Wenbo Wang ◽  
Guang Xi

This paper presents a multi-objective optimization-based intelligence design method for the design of the three-dimensional vaned diffuser for a given centrifugal compressor. This design method consists of three-dimensional vaned diffuser design model and its solving strategy. The three-dimensional vaned diffuser design model consists of the diffuser geometry mathematical model, performance evaluation model, objective equation, and design space. The diffuser geometry is described by the mathematical model of the meridional configurations and vane camber, trailing edge lean, and thickness. The generic design space is determined through literature statistical investigation. An NSGA-II multi-objective optimization algorithm, utilized to solve the three-dimensional vaned diffuser design model, directs the diffuser geometry variables to achieve the maximum stage isentropic efficiency and static pressure ratio at the design point within the design space automatically and intelligently. The presented three-dimensional vaned diffuser design method is demonstrated using a case test for a centrifugal impeller. The convergence of evolutionary solving for this three-dimensional vaned diffuser model is analyzed in detail, which provides the convergence reference for engineering applications. Three representative three-dimensional vaned diffusers on Pareto front are utilized to check the diversity of geometry shape and overall range performance characteristics. The results show that the three-dimensional vaned diffuser design method established here has excellent potential in automated design and maximizing stage performance. The method reported here could provide a valuable reference for the intelligent design of radial turbomachinery diffusers.


Author(s):  
Joseph T. Hamrick

Before and during World War Il the design and development of single stage, high pressure ratio centrifugal compressors was essentially a cut and try exercise. To reach a high pressure without substantial experimentation required multiple stages of impellers and diffusers with pressure ratios in the two to one range. While such arrangements were satisfactory for commercial use where weight was not a major consideration, they were not suitable for jet engines. The centrifugal compressor for the Whittle engine, the first British jet engine, was developed by trial and error with numerous modifications of the hub-shroud profile. The centrifugal compressor section of the National Advisory Committee for Aeronautics (NACA) designed, built and tested three compressor impellers during and after World War Il. They were part of a program designed to evaluate various blade shapes, but encountered such instabilities at the design pressure ratios that the experimental results led to no definitive conclusions. In 1948 the Centrifugal Compressor Section was given the assignment to further investigate the three impellers. The investigation led to the development of a quasi three dimensional design procedure that eliminated the guesswork from the basic design of a centrifugal impeller. Since the 1948 to 1955 time period over which the procedure was developed, the advances in computers have allowed refinements in the original computational methods. It is the objective of this presentation to review the history of the NACA centrifugal compressor program and efforts that have led to the latest developments in computational design procedures.


Author(s):  
Xu Yu-dong ◽  
Li Cong ◽  
Lv Qiong-ying ◽  
Zhang Xin-ming ◽  
Mu Guo-zhen

In order to study the effect of the trailing edge sweep angle of the centrifugal impeller on the aerodynamic performance of the centrifugal compressor, 6 groups of centrifugal impellers with different bending angles and 5 groups of different inclination angles were designed to achieve different impeller blade trailing edge angle. The computational fluid dynamics (CFD) method was used to simulate and analyze the flow field of centrifugal compressors with different blade shapes under design conditions. The research results show that for transonic micro centrifugal compressors, changing the blade trailing edge sweep angle can improve the compressor’s isentropic efficiency and pressure ratio. The pressure ratio of the compressor shows a trend of increasing first and then decreasing with the increase of the blade bending angle. When the blade bending angle is 45°, the pressure ratio of the centrifugal compressor reaches a maximum of 1.69, and the isentropic efficiency is 67.3%. But changing the inclination angle of the blade trailing edge has little effect on the isentropic efficiency and pressure ratio. The sweep angle of blade trailing edge is an effective method to improve its isentropic efficiency and pressure ratio. This analysis method provides a reference for the rational selection of the blade trailing edge angle, and provides a reference for the design of micro centrifugal compressors under high Reynolds numbers.


Author(s):  
E Swain

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.


Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.


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