Two Dimensional Optimization of Centrifugal Compressor Impellers Using Online Quasi-3D Flow Solver and Genetic Algorithm

2010 ◽  
Author(s):  
Ying Ma ◽  
Abraham Engeda
Keyword(s):  
Genetic Algorithm ◽  
Centrifugal Compressor ◽  
Search Algorithm ◽  
Radial Basis Function Network ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Modeling Tools ◽  
Flow Solver ◽  
Performance Map ◽  
A Performance

Modeling tools are widely used to create a performance map and decrease design cycle time in computer-aided centrifugal compressor impeller optimization procedures. However, a high-dimensional performance map is difficult to create and application of the approximate performance map brings errors into optimization procedures. This paper presents an online flow solver optimization procedure, in which a Quasi-three dimensional flow solver is directly used to evaluate impeller performances in the genetic algorithm (GA). Also, this procedure is compared with offline flow solver optimization procedure. In offline flow optimization procedure, the flow solver is employed to calculate performances in training database for creating a performance map trained by one type of artificial neural network (ANN), radial basis function network (RBFN). This performance map is further used to calculate the performances of impeller geometries. Results of these two optimization procedures under same GA parameters setting are compared and show that online flow solver optimization procedure can find better optima than offline flow solver optimization procedure. Moreover, influences of GA operators, parameters and local search algorithm on online flow solver optimization procedure are also investigated.

A Genetic Algorithm Approach to the Problem of Minimum Ship Wave Resistance

2002 ◽  
Vol 39 (03) ◽  
pp. 187-195
Author(s):  
Roko Dejhalla ◽  
Zoran Mrša ◽  
Senka Vukovic´
Keyword(s):  
Genetic Algorithm ◽  
Potential Flow ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Wave Resistance ◽  
Ship Hull ◽  
Point Of View ◽  
Flow Solver ◽  
Genetic Algorithm Approach

A genetic algorithm-based optimization method is proposed for an optimization of a ship hull from a hydrodynamic point of view. In the optimization procedure, the wave resistance has been selected as an objective function. The genetic algorithm is coupled with a computer program for solving the three-dimensional potential flow around a ship hull. The potential flow solver is based upon the well-known Dawson method. The optimization procedure has been applied to the Series 60 CB = 0.60 hull taken as a basis hull. The computational examples show the optimization ability of the proposed method.

Improved centrifugal compressor impeller optimization with a radial basis function network and principle component analysis

2010 ◽  
Vol 224 (4) ◽  
pp. 935-945 ◽  
Author(s):  
Y Ma ◽  
A Engeda ◽  
M Cave ◽  
J-L Di Liberti
Keyword(s):  
Radial Basis Function ◽  
Centrifugal Compressor ◽  
Basis Function ◽  
Radial Basis Function Network ◽  
Optimization Procedure ◽  
Component Analysis ◽  
Computational Time ◽  
Radial Basis ◽  
Compressor Impeller ◽  
Function Network

The development of a fast and reliable computer-aided design and optimization procedure for centrifugal compressors has attracted a great deal of attention both in the industry and in academia. Artificial neural networks (ANNs) have been widely used to create an approximate performance map to substitute the direct application of flow solvers in the optimization procedure. Although ANNs greatly decrease the computational time for the optimization, their accuracies still limit their applications. Furthermore, ANNs also bring errors to the final results. In this study, principal component analysis (PCA) or independent component analysis (ICA) is applied to transform the training database and make a radial basis function network (RBFN), a type of ANN, trained in a new coordinate system. The present study compares the accuracies of three different trained ANNs: RBFN, RBFN with PCA, and RBFN with ICA. Furthermore, the total performances of the centrifugal compressor impeller optimization procedures using these three different trained ANNs are compared. Genetic algorithm (GA) is used as an optimization method in the optimization procedure and influences of GA parameters on the optimization procedure performances are also studied. All results demonstrate that the application of PCA significantly increases the accuracy of trained ANN as well as the total performance of the centrifugal compressor impeller optimization procedure.

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.

Multi-Disciplinary Optimization of a Centrifugal Compressor for Micro-Turbine Applications

2016 ◽  
Author(s):  
Andrea Perrone ◽  
Luca Ratto ◽  
Gianluca Ricci ◽  
Francesca Satta ◽  
Pietro Zunino
Keyword(s):  
Mechanical Behavior ◽  
Centrifugal Compressor ◽  
Transport Model ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Aerodynamic Performance ◽  
Multidisciplinary Optimization ◽  
Navier Stokes ◽  
Phase Lag ◽  
High Rotational Speed

The present paper presents the multi-disciplinary optimization of a centrifugal compressor for a 100kW micro gas turbine. The high rotational speed fixed by the cycle optimization (75,000 rpm) required a simultaneous analysis of flow aerodynamics and mechanical behavior to account for the high centrifugal stresses the blades are subjected to, while maximizing the aerodynamic performance. A commercial 3D (three dimensional) computational fluid dynamics (CFD) solver adopted for the aerodynamic computations and an open source finite element FEM code for the mechanical integrity calculations have been coupled with metamodels to speed up the optimization process. Home-made scripting modules, which manage multidisciplinary optimization, mesh generation, geometry parameterization and result post-processing have been written and utilized. A sample data-base has been generated on the basis of the parameters selected to describe aerodynamic and mechanical constraints, and an optimization procedure based on a genetic algorithm has been performed. A RANS (Reynold Averaged Navier Stokes) steady approach with a two-equation SST (Shear Stress Transport) model has been adopted for the aerodynamic computations during the optimization procedure. The optimized compressor so achieved showed an important boost in aerodynamic performance, without any penalty in the mechanical behavior, as compared with the preliminary design. The optimized configuration has been tested also by means of URANS (Unsteady Reynolds Averaged Navier Stokes) phase-lag investigations, which confirmed the aerodynamic performance increase predicted by steady RANS calculations.

Full Annulus Simulation of a High-Speed Centrifugal Compressor Using an Unstructured RANS Flow Solver

2004 ◽  
Author(s):  
Chunhua Sheng
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Three Dimensional ◽  
Air Injection ◽  
Governing Equations ◽  
Flow Solver ◽  
The Stability ◽  
Sliding Technique ◽  
Stability Enhancement ◽  
Air Streams

This paper presents numerical simulations for a high-speed centrifugal compressor using an unstructured Reynolds averaged Naiver-Stokes flow solver U2NCLE. It solves three-dimensional compressible governing equations using an arbitrary Mach number solution algorithm. The stability enhancement for a centrifugal compressor was achieved by injecting air streams into the vaneless region of the diffuser. Numerical prediction of the stabilizing effect of air injection in the centrifugal compressor requires full annulus simulations of the compressor system. This work presents numerical procedures for simulating full annulus centrifugal compressor, including air injection modeling. A sliding technique is employed to handle relative motion grids for impeller and diffuser interactions. Computed results for the centrifugal compressor are analyzed and assessed with the experiment.

A Fast Method for Conjugate Heat Transfer Analysis of Centrifugal Compressor

2007 ◽  
Author(s):  
Vai-Man Lei ◽  
Tomoki Kawakubo
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Centrifugal Compressor ◽  
Conjugate Heat Transfer ◽  
Three Dimensional ◽  
Setup Time ◽  
Heat Transfer Analysis ◽  
Fast Method ◽  
Flow Solver ◽  
Indispensable Tool

The capability to calculate impeller temperature distribution is important to the life estimation of a centrifugal compressor. Three dimensional conjugate heat transfer (3D CHT) analysis with a high fidelity flow solver has become an indispensable tool for this class of problem. However, the application of 3D CHT analysis in the preliminary design of centrifugal compressor, which may involve the rapid evaluation of a large number of different configurations, is limited by the computation resource and setup time requirement. This paper presents a method of conjugate heat transfer analysis for centrifugal compressor design that requires significantly less computation power and setup time. The method, which consists of a one-dimensional flow model of the gas path and an axisymmetric CHT/flow solver, has been evaluated with data from 3D CHT analysis and experiment. Good agreement in impeller temperature distribution, as well as in impeller temperature trends due to changes in operating condition are obtained. To demonstrate the application of this method, various strategies to lower the impeller temperature are evaluated and discussed.

Design Optimization of Profiled Endwall in a High Work Turbine

2014 ◽  
Author(s):  
Huimin Tang ◽  
Shuaiqiang Liu ◽  
Hualing Luo
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Optimization Procedure ◽  
Flow Solver ◽  
Turbine Efficiency ◽  
Spline Surface ◽  
Improved Performance ◽  
Steady Simulation ◽  
High Work ◽  
Profile Loss

In this paper, a method based on non-uniform rational B-spline surface (NURBS) technique coupled with mesh deforming technique is implemented to design the profiled endwall of turbines. This method has the advantages of flexible geometry representation and automatic rapid remeshing. An optimization procedure has been implemented by integrating the in-house geometry manipulator, a commercial three-dimensional CFD flow solver and the optimization driver, IsightTM. This procedure is applied to design the profiled endwalls of the first stage of a one-and-half stage high work axial flow turbine. Genetic Algorithm is used in the optimization process, and the aim is to minimize the total pressure loss. The influences of the profiled endwalls on the secondary flow in the stator and rotor have been analyzed by steady simulation. The results indicate a 0.4% improvement in stage efficiency. The secondary loss as well as the profile loss has been significantly reduced, and the increase of the reaction which influences the turbine efficiency is also observed. The unsteady simulations are also presented in this paper to confirm the improved performance of the optimum profiled endwalls.

Compressor Leading Edge Sensitivities and Analysis With an Adjoint Flow Solver

2013 ◽  
Author(s):  
A. Giebmanns ◽  
J. Backhaus ◽  
C. Frey ◽  
R. Schnell
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Optimization Procedure ◽  
Engine Operation ◽  
Flow Solver ◽  
Fan Blade ◽  
Operation Results ◽  
Transonic Fan ◽  
Geometric Changes

Based on the results of a prior study about fan blade degradation, which state a noticeable influence of small geometric changes on the fan performance, an adjoint computational fluid dynamics method is applied to systematically analyze the sensitivities of fan blade performance to changes of the leading edge geometry. As early as during manufacture, blade geometries vary due to fabrication tolerances. Later, when in service, engine operation results in blade degradation which can be reduced but not perfectly fixed by maintenance, repair and overhaul processes. The geometric irregularities involve that it is difficult to predict the blade’s aerodynamic performance. Therefore, the aim of this study is to present a systematic approach for analyzing geometric sensitivities for a fan blade. To demonstrate the potential, two-dimensional optimizations of three airfoil sections at different heights of a transonic fan blade are presented. Although the optimization procedure is limited to the small area of the leading edge, the resulting airfoil sections can be combined to a three-dimensional fan blade with an increased isentropic efficiency compared to the initial blade. Afterwards, an adjoint flow solver is applied to quasi-three-dimensional configurations of an airfoil section in subsonic flow with geometric leading edge variations in orders representative for realistic geometry changes. Validations with non-linear simulation results demonstrate the high quality of the adjoint results for small geometric changes and indicate physical effects in the leading edge region that influence the prediction quality.

Dimensioning a recovery boiler furnace using mathematical optimization

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 119-129 ◽  
Author(s):  
VILJAMI MAAKALA ◽  
PASI MIIKKULAINEN
Keyword(s):  
Radial Basis Function Network ◽  
High Capacity ◽  
Mathematical Optimization ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Performance Criteria ◽  
Boiler Furnace ◽  
Starting Point ◽  
Recovery Boiler ◽  
Base Design

Capacities of the largest new recovery boilers are steadily rising, and there is every reason to expect this trend to continue. However, the furnace designs for these large boilers have not been optimized and, in general, are based on semiheuristic rules and experience with smaller boilers. We present a multiobjective optimization code suitable for diverse optimization tasks and use it to dimension a high-capacity recovery boiler furnace. The objective was to find the furnace dimensions (width, depth, and height) that optimize eight performance criteria while satisfying additional inequality constraints. The optimization procedure was carried out in a fully automatic manner by means of the code, which is based on a genetic algorithm optimization method and a radial basis function network surrogate model. The code was coupled with a recovery boiler furnace computational fluid dynamics model that was used to obtain performance information on the individual furnace designs considered. The optimization code found numerous furnace geometries that deliver better performance than the base design, which was taken as a starting point. We propose one of these as a better design for the high-capacity recovery boiler. In particular, the proposed design reduces the number of liquor particles landing on the walls by 37%, the average carbon monoxide (CO) content at nose level by 81%, and the regions of high CO content at nose level by 78% from the values obtained with the base design. We show that optimizing the furnace design can significantly improve recovery boiler performance.

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