Design of Industrial Axial Compressor Blade Sections for Optimal Range and Performance

2003 ◽  
Author(s):  
Frank Sieverding ◽  
Beat Ribi ◽  
Michael Casey ◽  
Michael Meyer
Keyword(s):  
Genetic Algorithm ◽  
Fitness Function ◽  
Optimization Technique ◽  
Axial Compressor ◽  
Design System ◽  
Flow Solver ◽  
Axial Compressors ◽  
Mechanical Constraints ◽  
And Performance ◽  
Operating Points

A design system for the blade sections of industrial axial compressors has been developed. The method combines a parametric geometry definition method, a powerful blade-to-blade flow solver (MISES) and an optimization technique (breeder genetic algorithm) with an appropriate fitness function. Particular effort has been devoted to the design of the fitness function for this application which includes non-dimensional terms related to the required performance at design and off-design operating points. It has been found that essential aspects of the design (such as the required flow turning, or mechanical constraints) should not be part of the fitness function, but need to be treated as so-called “killer” criteria in the genetic algorithm. Finally, it has been found worthwhile to examine the effect of the weighting factors of the fitness function to identify how these affect the performance of the sections. The system has been tested on the design of a repeating stage for the middle stages of an industrial axial compressor. The resulting profiles show an increased operating range compared to an earlier design using NACA65 profiles.

Design of Industrial Axial Compressor Blade Sections for Optimal Range and Performance

2004 ◽  
Vol 126 (2) ◽  
pp. 323-331 ◽  
Author(s):  
Frank Sieverding ◽  
Beat Ribi ◽  
Michael Casey ◽  
Michael Meyer
Keyword(s):  
Genetic Algorithm ◽  
Gas Turbines ◽  
Fitness Function ◽  
Optimization Technique ◽  
Axial Compressor ◽  
Axial Flow ◽  
High Volume ◽  
Volume Flow ◽  
Design System ◽  
Operating Range

Background: The blade sections of industrial axial flow compressors require a wider range from surge to choke than typical gas turbine compressors in order to meet the high volume flow range requirements of the plant in which they operate. While in the past conventional blade profiles (NACA65 or C4 profiles) at moderate Mach number have mostly been used, recent well-documented experience in axial compressor design for gas turbines suggests that peak efficiency improvements and considerable enlargement of volume flow range can be achieved by the use of so-called prescribed velocity distribution (PVD) or controlled diffusion (CD) airfoils. Method of approach: The method combines a parametric geometry definition method, a powerful blade-to-blade flow solver and an optimization technique (breeder genetic algorithm) with an appropriate fitness function. Particular effort has been devoted to the design of the fitness function for this application which includes non-dimensional terms related to the required performance at design and off-design operating points. It has been found that essential aspects of the design (such as the required flow turning, or mechanical constraints) should not be part of the fitness function, but need to be treated as so-called “killer” criteria in the genetic algorithm. Finally, it has been found worthwhile to examine the effect of the weighting factors of the fitness function to identify how these affect the performance of the sections. Results: The system has been tested on the design of a repeating stage for the middle stages of an industrial axial compressor. The resulting profiles show an increased operating range compared to an earlier design using NACA65 profiles. Conclusions: A design system for the blade sections of industrial axial compressors has been developed. Three-dimensional CFD simulations and experimental measurements demonstrate the effectiveness of the new profiles with respect to the operating range.

Some Aspects of the Transonic Compressor Tandem Design

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Alexander Hergt ◽  
S. Grund ◽  
J. Klinner ◽  
W. Steinert ◽  
M. Beversdorff ◽  
...  
Keyword(s):  
Mach Number ◽  
Design Space ◽  
Wake Flow ◽  
Objective Functions ◽  
Flow Solver ◽  
Axial Compressors ◽  
Transonic Compressor ◽  
And Performance ◽  
Transonic Cascade ◽  
Operating Points

For the development of the latest generation of axial compressors, it is necessary to enlarge the design space by using advanced aerodynamic processes. This enables a further increase in efficiency and performance. The use of a tandem blade configuration in a transonic compressor row provides the possibility to enlarge the design space. It is necessary to address the design aspects a bit more in detail in order to efficiently apply this blading concept to turbomachinery. Therefore, in the current study, the known design aspects of tandem blading in compressors will be summed up under the consideration of the aerodynamic effects and construction characteristics of a transonic compressor tandem. Based on this knowledge, a new transonic compressor tandem cascade (DLR TTC) with an inflow Mach number of 0.9 is designed using modern numerical methods and a multi-objective optimization process. Three objective functions as well as three operating points are used in the optimization. Furthermore, both tandem blades and their arrangement are parameterized. From the resulting database of 1246 members, a final best member is chosen as the state-of-the-art design for further detailed investigation. The aim of the ensuing experimental and numerical investigation is to answer the question, whether the tandem cascade resulting from the modern design process fulfills the described design aspects and delivers the requested performance and efficiency criteria. The numerical simulations within the study are carried out with the DLR flow solver TRACE. The experiments are performed at the transonic cascade wind tunnel of DLR in Cologne. The inflow Mach number during the tests is 0.9, and the AVDR is adjusted to 1.3 (design value). Wake measurements with a three-hole probe are carried out in order to determine the cascade performance. The experimental results show an increase in losses and a reduction of the cascade deflection by about 2 deg compared to the design concept. Nevertheless, the experimental and numerical results allow a good understanding of the aerodynamic effects. In addition, planar PIV was applied in a single S1 plane located at midspan to capture the velocity field in the wake of blade 1 in order to analyze the wake flow in detail and describe its influence on the cascade deflection and loss behavior. Finally, an outlook will be given on what future tandem compressor research should be focused.

scholarly journals Simplified Method for Flow Analysis and Performance Calculation Through an Axial Compressor

1984 ◽  
Author(s):  
Hubert Miton ◽  
Youssef Doumandji ◽  
Jacques Chauvin
Keyword(s):  
Equations Of Motion ◽  
Computing Time ◽  
Flow Analysis ◽  
Axial Compressor ◽  
Computation Method ◽  
Duct Flow ◽  
Axial Compressors ◽  
Flow Through ◽  
And Performance ◽  
Performance Calculation

This paper describes a fast computation method of the flow through multistage axial compressors of the industrial type. The flow is assumed to be axisymmetric between the blade rows which are represented by actuator disks. Blade row losses and turning are calculated by means of correlations. The equations of motion are linearized with respect to the log of static pressure, whose variation along the radius is usually of limited extent for the type of machines for which the method has been developed. In each computing plane (i.e. between the blade rows) two flows are combined: a basic flow with constant pressure satisfying the mass flow requirements and a perturbation flow fulfilling the radial equilibrium condition. The results of a few sample calculations are given. They show a satisfactory agreement with a classical duct flow method although the computing time is reduced by a factor five. The method has also been coupled with a surge line prediction calculation.

Numerical Characterization of a HP Compressor Stage Equipped With a Closed Shrouded Stator Cavity

2020 ◽  
Author(s):  
Cedric Babin ◽  
Michel Dumas ◽  
Xavier Ottavy ◽  
Fabrizio Fontaneto
Keyword(s):  
Axial Compressor ◽  
Second Phase ◽  
Cavity Flows ◽  
Flow Topology ◽  
Closed Cavity ◽  
Axial Compressors ◽  
Numerical Characterization ◽  
Performance Effects ◽  
And Performance ◽  
Final Extent

Abstract In axial compressors, shrouded stator cavity flows are responsible for performance degradation due to their interaction with the power stream. The present paper aims at exploring the possibility of employing a single stage high pressure axial compressor as a test vehicle for cavity flows investigations. In a first step, the robustness of the adopted RANS approach is tested against experimental data on the closed-cavity baseline configuration (i.e. no downstream-to-upstream recirculation). In a second phase, the effect of different hub cavities layouts of different levels of realism is numerically investigated. The focus is set on the representativeness of a closed cavity configuration with injection. The cavity flow topology and impact on the overall performance are considered in the analysis. At its final extent, this paper provides numerical and experimental guidelines for the robust assessment of cavity flows topology and performance effects.

Research on Optimization of the Design(Inverse) Issue of S2 Surface of Axial Compressor Based on Genetic Algorithm

2020 ◽  
Author(s):  
Zijing Chen ◽  
Bo Liu ◽  
Xiaoxiong Wu
Keyword(s):  
Genetic Algorithm ◽  
Total Pressure ◽  
Fitness Function ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Local Data ◽  
Real Coded Genetic Algorithm ◽  
Overall Efficiency ◽  
Total Pressure Ratio ◽  
Peak Value

Abstract In order to further improve the effectiveness of design(inverse) issue of S2 surface of axial compressor, a design method of optimization model based on real-coded genetic algorithm is instructed, with a detailed description of some important points such as the population setting, the fitness function design and the implementation of genetic operator. The method mainly takes the pressure ratio, the circulation as the optimization variables, the total pressure ratio and the overall efficiency of the compressor as the constraint condition and the decreasing of the diffusion factor of the compressor as the optimization target. In addition, for the propose of controlling the peak value of some local data after the optimization, a local optimization strategy is proposed to make the method achieve better results. In the optimization, the streamline curvature method is used to perform the iterative calculation of the aerodynamic parameters of the S2 flow surface, and the polynomial fitting method is used to optimize the dimensionality of the variables. The optimization result of a type of ten-stage axial compressor shows that the pressure ratio and circulation parameters have significant effect on the diffusion factor’s distribution, especially for the rotor pressure ratio. Through the optimization, the smoothness of the mass-average pressure ratio distribution curve of the rotors at all stages of the compressor is improved. The maximum diffusion factors in spanwise of rotor rows at the first, fifth and tenth stage of the compressor are reduced by 1.46%, 12.53% and 8.67%, respectively. Excluding the two calculation points at the root and tip of the blade because of the peak value, the average diffusion factors in spanwise are reduced by 1.28%, 3.46%, and 1.50%, respectively. For the two main constraints, the changes of the total pressure ratio and overall efficiency are less than 0.03% and 0.032%, respectively. In the end, a 3-d CFD numerical result is given to testify the effects of the optimization, which shows that the loss in the compressor is decreased by the optimization algorithm.

Axis-Asymmetric Profiled Endwall Design by Using Multiobjective Optimisation Linked With 3D RANS-Flow-Simulations

2007 ◽  
Author(s):  
Christian Dorfner ◽  
Eberhard Nicke ◽  
Christian Voss
Keyword(s):  
The Novel ◽  
3D Flow ◽  
Flow Solver ◽  
Axial Compressors ◽  
Flow Simulations ◽  
Flow Loss ◽  
Engine Components ◽  
Operating Points ◽  
Isentropic Efficiency ◽  
Wide Operating

Secondary flow loss in modern axial compressors is considered to be the prime reason for the reduction of overall isentropic efficiency in these engine components. This paper presents a new methodology to diminish blade secondary loss and endwall loss by an axis-asymmetric modification of endwalls using an automated multiobjective optimizer in conjunction with 3D-RANS-flow-simulations. In order to obtain a favorable design for a wide operating range, the most important operating-points are considered in the optimization process. The existing multiobjective optimization package is enhanced by implementation of DLR’s in-house 3D-flow-solver TRACE. A straightforward stator optimization was performed for a 3D-process-chain test run. Finally, the novel endwall design technique is introduced and the first optimization results and further studies are discussed.

An Integrated Design System for Fans, Compressors, and Turbines: Part 4 — Through-Flow Solver

2005 ◽  
Author(s):  
Allen Medlock ◽  
Max J. Miller ◽  
S. Murthy Konan ◽  
Ben Chambers ◽  
Bao Q. Nguyen
Keyword(s):  
Integrated Design ◽  
Design System ◽  
Aerodynamic Design ◽  
Flow Paths ◽  
Flow Solver ◽  
Axial Compressors ◽  
Interactive Interface ◽  
Through Flow ◽  
Design Cycle ◽  
Access Information

A new aerodynamic design system has been developed that includes a through-flow solver for fans, axial compressors and turbines, and radial compressors and turbines. Three earlier papers gave an overview of the system and described the interactive interface and geometry generators. This paper focuses on several special features in the through-flow solver that provide increases in aerodynamic designer productivity. Some of the key features are stations decoupled from flow paths, ability to accept a wide variety of input parameters, use of gas property routines, ability to inject flow non-uniformly with a different composition than the main flow gas composition, ability to access information from several airfoil geometry generator solutions, and clear, comprehensive error handling. These special features and others have provided major savings from productivity improvements and reductions in design cycle time.

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.

Research on GA-ANN Integration and Its Applications to Cold Extrusion Process Design

2006 ◽  
Vol 532-533 ◽  
pp. 897-900
Author(s):  
Ting Wei Ji ◽  
Jun Gao ◽  
Guo Qun Zhao ◽  
Cheng Rui Zhang
Keyword(s):  
Genetic Algorithm ◽  
Process Design ◽  
Binary Code ◽  
Fitness Function ◽  
Extrusion Process ◽  
Selection Method ◽  
Cold Extrusion ◽  
Design System ◽  
Roulette Wheel Selection ◽  
Roulette Wheel

Based on the research of the functions of ANN-based cold extrusion process design system, genetic algorithm (GA) is proposed to optimize the topology and parameters of artificial neural networks (ANN), in order to improve the running efficiency of the networks. The binary encoding approach is implemented to represent the GA chromosome. The code string or the chromosome was divided into three parts: the first part is the binary code of the cold extruded part; the second part is the binary code of the topology and parameters of ANN; the last is the binary code of the semi-cold-extruded-part or the billet. The 1/F(X) function is selected as the fitness function in GA, where, X represents the binary code of the cold extruded part, F(X) represents the error between the real outputs of ANN and the desired results; the biased roulette wheel selection method is used for selecting operation in this paper; two-point crossover and one-point mutation are selected for these two types of genetic operations. Finally, the typical cold extruded part is used for verification as an example by using the optimized ANN, the result shows that ANN optimized by GA has efficiency and validity in the cold extrusion process design system.

scholarly journals Optimization of Biofilter Size for Aquaponics Using Genetic Algorithm

2021 ◽  
Vol 25 (5) ◽  
pp. 632-638
Author(s):  
Amir A. Bracino ◽  
Jason L. Española ◽  
Argel A. Bandala ◽  
Elmer P. Dadios ◽  
Edwin Sybingco ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Loading Rate ◽  
Fitness Function ◽  
Optimization Technique ◽  
Water Flow Rate ◽  
Nitrifying Bacteria ◽  
Design Parameters ◽  
Heuristic Solution ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading

Unlike a media-filled aquaponic system, the nutrient film technique (NFT) and deep water culture (DWC) require the installation of an external biofilter to provide sufficient area for nitrifying bacteria colonization, which is essential for the conversion of toxic ammonia from fish waste into nitrate that is easily assimilated by plants. Given the importance of biofilters, it is imperative to properly design this tank to effectively support the nitrification process. Several factors need to be considered for the biofilter design. Thus, an optimization algorithm can be used to obtain combinations of the design parameters. The genetic algorithm (GA) is a heuristic solution search or optimization technique based on the Darwinian principle of genetic selection. The main goal of this study was to obtain the optimal biofilter size for a given fishpond volume and the amount of ammonia to be treated. The conversion coefficient in the Michaelis–Menten equation was used as the fitness function in this study. The parameters optimized using GA include the hydraulic loading rate, height of the biofilter, and predicted ammonia concentration. For the given assumption of a 60 kg feed introduced to the system and a 1500 L fishpond, the hydraulic loading rate, biofilter height, and final concentration of ammonia were 0.17437 m, 0.58585 m, and 0.01026 ppm, respectively. Using the values obtained from running the GA, the optimum biofilter volume for the system was 0.4608 m3, whereas the water flow rate was 0.03 L/min. For recommendations, multiple objective GAs can be used to add cost-related variables in the optimization because they have not yet been considered in the computation.

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