Aerodynamic and Structure Considerations in Centrifugal Compressor Design: Blade Lean Effects

2012 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Centrifugal Compressor ◽  
Structural Reliability ◽  
Three Dimensional ◽  
Design System ◽  
Compressor Wheel ◽  
Through Flow ◽  
Compressor Design ◽  
Recent Developments ◽  
Compressor Performance ◽  
Wide Operating

Optimization procedures are demanded by turbomachinery industries that enable to enhance compressor efficiency and wide operating ranges. Most of the design processes focuseither on aerodynamics or structure. However, the compressor design is an integration between aerodynamics and structure. This paper presents some recent developments of the aerodynamic and structural integral design system. The design process including the meanline design, through-flow optimization and three-dimensional viscous analysis was used in the centrifugal compressor design. The aerodynamic and structural design need to be optimized at the same time. Normally most of the favorable aerodynamic features do not correspond with the structural reliability of the compressor wheel. The optimization between aerodynamic performance and structural reliability is critical to provide the maximal potential of the compressor performance. The main purpose of the current study is to discuss the importance of the aerodynamic and structural optimizations through a centrifugal compressor wheel lean effects. The study demonstrated that the integral design of the aerodynamics and structure is very important.

Aerodynamic Analysis in Lean Blade Effects in Centrifugal Compressor

2011 ◽  
Author(s):  
Cheng Xu ◽  
R. S. Amano ◽  
A. Alkhalidi
Keyword(s):  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Design System ◽  
Aerodynamic Optimization ◽  
Compressor Wheel ◽  
Structure Reliability ◽  
System A ◽  
Compressor Design ◽  
Recent Developments ◽  
Wide Operating

Turbomachinery industries are interested in using optimization procedures that enable to enhance compressor efficiency and wide operating ranges. Most of the design processes are focus on either in aerodynamics or structure. However, the compressor design is an integration between the aerodynamics and structure. This paper presents the recent developments of the aerodynamic integral design system. A design process including the meanline design, throughflow optimization and three-dimensional viscous analysis was used in the centrifugal compressor design. The aerodynamic design design needs to optimize at same time. Normally the most of performance of the favorite features are not friendly to the structure reliability of the compressor wheel. The optimization between aerodynamic performance and structure reliability is critical to provide the maximal potential of the compressor design. The main purpose of current paper is to discuss the importance of the aerodynamic optimization through lean effects. It can be seen from the discussion that the integration of aerodynamics is very important.

scholarly journals Analysis and Optimization of the Performances of the Centrifugal Compressor Using the CFD

2021 ◽  
Vol 39 (1) ◽  
pp. 107-120
Author(s):  
Brihmat Mostefa ◽  
Refassi Kaddour ◽  
Douroum Embarek ◽  
Kouadri Amar
Keyword(s):  
Centrifugal Compressor ◽  
Internal Flow ◽  
Design Tool ◽  
Design System ◽  
Optimization Approach ◽  
Original Design ◽  
Predicting Performance ◽  
Compressor Design ◽  
Current Design ◽  
Compressor Performance

Centrifugal compressors have been used in many areas of the machinery. The centrifugal compressor design is very complex, and a unique design system needs to be developed. A centrifugal compressor design system should be easy to use in interface and also flexible for inputs and outputs. The design tool also needs to be able to predicate the compressor performance in a fairly accurate level. In this study, we have developed a general analyses and optimization approach in the design and performance analysis of centrifugal turbomachines. This approach is based on different methods starting from a 1D approach up to the 3D study of the internal flow. It presents itself as a robust procedure for predicting and understanding the phenomena associated with the operation of turbomachines, but also for predicting performance. Current design system includes initial parameter studies, throughflow calculation, impeller design. The main improvements of the design system are adding the interface to allow users easy to use, adding the input and output capabilities and modifying few correlations. Current design system can predict the blade loading and compressor performance better compared with original design system. To check the aerodynamic appearance of the centrifugal compressor impeller blades, we must change the impeller dimensions and focus on changing axial length, but when changing the blade numbers, the model that improved efficiency and power at the same time introduced a design with a 0.274% and 10.735% improvement in each respectively in comparison to the initial impeller at the design point.

Automated Blade Optimization and 3D CFD Analysis for an Axial Multistage GT Compressor Redesign

2006 ◽  
Author(s):  
Lars Moberg ◽  
Gianfranco Guidati ◽  
Sasha Savic
Keyword(s):  
Flow Analysis ◽  
Optimization Methods ◽  
Design System ◽  
Cfd Analysis ◽  
Controlled Diffusion ◽  
Repetitive Tasks ◽  
Blade Optimization ◽  
Through Flow ◽  
Compressor Design ◽  
Linux Cluster

This paper focuses on (1) the basic compressor layout based on meridional through flow analysis and (2) the re-design of blades and vanes using sophisticated automated design optimization methods. All tools and processes are integrated into a consistent Compressor Design System, which runs on a powerful Linux cluster. This design system allows designing, analyzing and documenting blade design in mostly automated way. This frees the engineer from repetitive tasks and allows him to concentrate on a physical understanding and improvement of the compressor. The tools and methods are illustrated on the basis of an actual ALSTOM compressor. The main objectives of this upgrade are a modest increase in mass flow and an efficiency improvement. The latter is to be achieved through the replacement of NACA blades by modern Controlled Diffusion Airfoils (CDA). Results are presented including a CFD analysis of the front stages of the baseline and upgrade compressor.

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 Meridional Considerations of the Centrifugal Compressor Development

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Centrifugal Compressor ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Angle Distribution ◽  
High Pressure Ratio ◽  
Structure Reliability ◽  
Compressor Performance ◽  
Meridional Profile ◽  
Compressor Efficiency ◽  
Wide Operating

Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

A CFD Analysis of the Effects of Two-Phase Flow in a Two-Stage Centrifugal Compressor

2015 ◽  
Author(s):  
Chaitanya V. Halbe ◽  
Walter F. O’Brien ◽  
William T. Cousins ◽  
Vishnu Sishtla
Keyword(s):  
Centrifugal Compressor ◽  
Two Phase Flow ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Power Input ◽  
Phase Flow ◽  
Two Stage ◽  
Two Phase ◽  
Droplet Dynamics ◽  
Compressor Performance

The performance of a compressor is known to be affected by the ingestion of liquid droplets. Heat, mass and momentum transfer as well as the droplet dynamics are some of the important mechanisms that govern the two-phase flow. This paper presents numerical investigations of three-dimensional two-phase flow in a two-stage centrifugal compressor, incorporating the effects of the above mentioned mechanisms. The results of the two-phase flow simulations are compared with the simulation involving only the gaseous phase. The implications for the compressor performance, viz. the pressure ratio, the power input and the efficiency are discussed. The role played by the droplet-wall interactions on the rate of vaporization, and on the compressor performance is also highlighted.

A Deep Insight Into the Transonic Flow of an Advanced Centrifugal Compressor Design

2019 ◽  
Author(s):  
D. Wittrock ◽  
M. Junker ◽  
M. Beversdorff ◽  
A. Peters ◽  
E. Nicke
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Leading Edge ◽  
Free Form ◽  
Numerical Verification ◽  
Deep Insight ◽  
Flow Solver ◽  
Compressor Design ◽  
Design Speed

Abstract In the last decades major improvements in transonic centrifugal compressor design have been achieved. The further exploration of design space is enabled by recent progress in structural mechanics and manufacturing. A challenging task of inducer design especially in terms of transonic inflow conditions is to provide a wide flow range and reduced losses due to a sufficient shock control. The use of so called multidisciplinary design optimization with an extensive amount of free parameters leads finally to complex designs. DLR’s latest Fast Rotating Centrifugal Compressor (SRV5) operates at a design speed of Mu2 = 1.72 and a total pressure ratio of 5.72. This compressor design is characterized by an S-shaped leading edge and free-form blade surfaces. Due to the complex design the key design features are difficult to explore. Therefore, non-intrusive measurements are conducted on the highly loaded SRV5. The Laser-2-Focus (L2F) approach that is used in addition with the Doppler Global Velocimetry (DGV) delivers a three dimensional velocity field. Besides the impeller inflow the ouflow is also part of the experimental and numerical verification of the advanced compressor design. Experimental results are compared with the numerical analysis of the compressor using DLR’s RANS Flow Solver TRACE. The deep insight of the inflow leads to a better understanding of the operating behavior of such impeller designs.

scholarly journals Comparative Study of Unsteady Flows in a Transonic Centrifugal Compressor With Vaneless and Vaned Diffusers

2001 ◽  
Author(s):  
Michael M. Cui
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Power Laws ◽  
Working Fluid ◽  
Local Flow ◽  
Transonic Centrifugal Compressor ◽  
Compressor Performance ◽  
Overall Performance

To reduce vibration and noise level, the impeller and diffuser blade numbers inside an industrial compressor are typically chosen without common divisors. The shapes of volutes or collectors in these compressors are also not axis-symmetric. When impeller blades pass these asymmetric structures, the flow field in the compressor is time-dependent and three-dimensional. To obtain a fundamental physical understanding of these three-dimensional unsteady flow fields and assess their impact on the compressor performance, the flow field inside the compressors needs to be studied as a whole to include asymmetric and unsteady interaction between the compressor components. In current study, a unified three-dimensional numerical model was built for a transonic centrifugal compressor including impeller, diffusers, and volute. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws, respectively. The three-dimensional unsteady flow field was simulated with a Navier-Stokes solver using the k-ε turbulent model. The overall performance parameters are obtained by integrating the field quantities. Both unsteady flow field and overall performance are analyzed comparatively for each component. The compressor was tested in a water chiller system instrumented to obtain both overall performance data and local flow field quantities. The experimental and numerical results agree well. The correlation between the overall compressor performance and local flow field quantities is defined. The methodology developed and data obtained in these studies can be applied to centrifugal compressor design and optimization.

Modelling of spanwise mixing in compressor through-flow computations

1997 ◽  
Vol 211 (3) ◽  
pp. 243-251 ◽  
Author(s):  
J Dunham
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Streamline Curvature ◽  
Wall Boundary Layer ◽  
Through Flow ◽  
Compressor Design ◽  
Multistage Compressors ◽  
End Wall

Although three-dimensional Navier-Stokes computations are coming into use more and more, streamline curvature through-flow computations are still needed, especially for multistage compressors, and where codes which run in minutes rather than hours are preferred. These methods have been made more realistic by taking account of end-wall effects and spanwise mixing by four aerodynamic mechanisms: turbulent diffusion, turbulent convection by secondary flow, spanwise migration of aerofoil boundary layer fluid and spanwise convection of fluid in blade wakes. This paper describes the models adopted in the DRA streamline curvature method for axial compressor design and analysis. Previous papers are summarized briefly before describing the new part of the model—that accounting for aerofoil boundary layers and wakes. Other changes to the previously published annulus wall boundary layer model have been made to enable it to cater for separations and end bends. The resulting code is evaluated against a range of experimental and computational results.

Viscous Throughflow Modeling for Multistage Compressor Design

1993 ◽  
Vol 115 (2) ◽  
pp. 296-304 ◽  
Author(s):  
M. A. Howard ◽  
S. J. Gallimore
Keyword(s):  
Shear Force ◽  
High Speed ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Design System ◽  
Flow Angle ◽  
Axial Compressors ◽  
Dynamic Head ◽  
Viscous Shear ◽  
Compressor Design

An existing throughflow method for axial compressors, which accounts for the effects of spanwise mixing using a turbulent diffusion model, has been extended to include the viscous shear force on the endwall. The use of a shear force, consistent with a no-slip condition, on the annulus walls in the throughflow calculations allows realistic predictions of the velocity and flow angle profiles near the endwalls. The annulus wall boundary layers are therefore incorporated directly into the throughflow prediction. This eliminates the need for empirical blockage factors or independent annulus boundary layer calculations. The axisymmetric prediction can be further refined by specifying realistic spanwise variations of loss coefficient and deviation to model the three-dimensional endwall effects. The resulting throughflow calculation gives realistic predictions of flow properties across the whole span of a compressor. This is confirmed by comparison with measured data from both low and high-speed multistage machines. The viscous throughflow method has been incorporated into an axial compressor design system. The method predicts the meridional velocity defects in the endwall region and consequently blading can be designed that allows for the increased incidence, and low dynamic head, near the annulus walls.

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