Optimization of a Centrifugal Impeller Using Evolutionary Algorithms

Volume 6: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2008-50805 ◽

2008 ◽

Cited By ~ 2

Author(s):

Andreas Bartold ◽

Franz Joos

Keyword(s):

Evolutionary Algorithms ◽

Three Dimensional ◽

Optimization Method ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Aerodynamic Design ◽

B Spline ◽

Spline Curves ◽

Automated Optimization ◽

Isentropic Efficiency

This paper presents the development and application of an automated optimization method for aerodynamic design of centrifugal impellers. The algorithm used for the optimization is an evolutionary algorithm. Within this method the shape of the centrifugal impeller is described using B-Spline curves. The method introduced is used for redesigning an existing impeller with regard to maximization of the isentropic efficiency at a fixed operating point. Here the isentropic efficiency is calculated using the solution of a compressible three-dimensional Reynolds-averaged Navier-Stokes solver. The presentation will show that the method presented provides a new design that outperforms the original impeller with respect to the particular objective and demonstrates its usefulness.

Download Full-text

The Extension of a Solution-Adaptive Three-Dimensional Navier–Stokes Solver Toward Geometries of Arbitrary Complexity

Journal of Turbomachinery ◽

10.1115/1.2929234 ◽

1993 ◽

Vol 115 (2) ◽

pp. 283-295 ◽

Cited By ~ 14

Author(s):

W. N. Dawes

Keyword(s):

Guide Vane ◽

Three Dimensional ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Transonic Compressor ◽

Compressor Rotor ◽

Wide Range ◽

Nozzle Guide Vane ◽

Recent Developments ◽

Nozzle Guide

This paper describes recent developments to a three-dimensional, unstructured mesh, solution-adaptive Navier–Stokes solver. By adopting a simple, pragmatic but systematic approach to mesh generation, the range of simulations that can be attempted is extended toward arbitrary geometries. The combined benefits of the approach result in a powerful analytical ability. Solutions for a wide range of flows are presented, including a transonic compressor rotor, a centrifugal impeller, a steam turbine nozzle guide vane with casing extraction belt, the internal coolant passage of a radial inflow turbine, and a turbine disk cavity flow.

Download Full-text

Numerical Study of the Internal Flow Field of a Centrifugal Impeller

Volume 1: Turbomachinery ◽

10.1115/94-gt-357 ◽

1994 ◽

Cited By ~ 2

Author(s):

Mou-jin Zhang ◽

Chuan-gang Gu ◽

Yong-miao Miao

Keyword(s):

Flow Field ◽

Stokes Equations ◽

Numerical Study ◽

Three Dimensional ◽

Simple Algorithm ◽

Internal Flow ◽

Staggered Grid ◽

Navier Stokes ◽

Centrifugal Impeller ◽

High Reynolds

The complex three-dimensional flow field in a centrifugal impeller with low speed is studied in this paper. Coupled with high–Reynolds–number k–ε turbulence model, the fully three–dimensional Reynolds averaged Navier–Stokes equations are solved. The Semi–Implicit Method for Pressure–Linked Equations (SIMPLE) algorithm is used. And the non–staggered grid arrangement is also used. The computed results are compared with the available experimental data. The comparison shows good agreement.

Download Full-text

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

Journal of Turbomachinery ◽

10.1115/1.2927419 ◽

1990 ◽

Vol 112 (1) ◽

pp. 44-49 ◽

Cited By ~ 1

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.

Download Full-text

Aerodynamic Design and Performance of Aspirated Airfoils

Journal of Turbomachinery ◽

10.1115/1.1519834 ◽

2003 ◽

Vol 125 (1) ◽

pp. 141-148 ◽

Cited By ~ 12

Author(s):

Ali Merchant

Keyword(s):

Guide Vane ◽

Three Dimensional ◽

High Loading ◽

Navier Stokes ◽

Aerodynamic Design ◽

Design Studies ◽

Controlled Diffusion ◽

And Performance ◽

The Impact ◽

Profile Loss

The impact of boundary layer aspiration, or suction, on the aerodynamic design and performance of turbomachinery airfoils is discussed in this paper. Aspiration is studied first in the context of a controlled diffusion cascade, where the effect of discrete aspiration on loading levels and profile loss is computationally investigated. Blade design features which are essential in achieving high loading and minimizing the aspiration requirement are described. Design studies of two aspirated compressor stages and an aspirated turbine exit guide vane using three dimensional Navier-Stokes calculations are presented. The calculations show that high loading can be achieved over most of the blade span with a relatively small amount of aspiration. Three dimensional effects close to the endwalls are shown to degrade the performance to varying degrees depending on the loading level.

Download Full-text

Application of a Three-Dimensional Inverse Method to the Design of a Centrifugal Compressor Impeller

Volume 1: Turbomachinery ◽

10.1115/98-gt-127 ◽

1998 ◽

Cited By ~ 1

Author(s):

Alain Demeulenaere ◽

Olivier Léonard ◽

René Van den Braembussche

Keyword(s):

Centrifugal Compressor ◽

Inverse Method ◽

Three Dimensional ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Mean Velocity ◽

Blade Shape ◽

Compressor Impeller ◽

Real Performance ◽

The Mean

The use of a three-dimensional Euler inverse method for the design of a centrifugal impeller is demonstrated. Both the blade shape and the endwalls are iteratively designed. The meridional contour is modified in order to control the mean velocity level in the blade channel, while the blade shape is designed to achieve a prescribed loading distribution between the inlet and the outlet. The method salves the time dependent Euler equations in a numerical domain of which some boundaries (the blades or the endwalls) move and change shape during the transient part of the computation, until a prescribed pressure distribution is achieved on the blade surfaces. The method is applied to the design of a centrifugal compressor impeller, whose hub endwall and blade surfaces are modified by the inviscid inverse method. The real performance of both initial and modified geometries are compared through three-dimensional Navier-Stokes computations.

Download Full-text

Simulation of the subsonic flow in a high-speed centrifugal compressor impeller by the pressure-based method

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/0957650981536790 ◽

1998 ◽

Vol 212 (4) ◽

pp. 269-287 ◽

Cited By ~ 1

Author(s):

Y Wang ◽

S Komori

Keyword(s):

High Speed ◽

Compressible Flows ◽

Incompressible Flows ◽

Stokes Equations ◽

Three Dimensional ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Navier Stokes Equations ◽

Compressor Impeller ◽

Collocated Grid

A pressure-based finite volume procedure developed previously for incompressible flows is extended to predict the three-dimensional compressible flow within a centrifugal impeller. In this procedure, the general curvilinear coordinate system is used and the collocated grid arrangement is adopted. Mass-averaging is used to close the instantaneous Navier-Stokes equations. The covariant velocity components are used as the main variables for the momentum equations, making the pressure-velocity coupling easier. The procedure is successfully applied to predict various compressible flows from subsonic to supersonic. With the aid of the k-ɛ turbulence model, the flow details within a centrifugal impeller are obtained using the present procedure. Predicted distributions of the meridional velocity and the static pressure are reasonable. Calculated radial velocities and flow angles are favourably compared with the measurements at the exit of the impeller.

Download Full-text

A Simulation of the Unsteady Interaction of a Centrifugal Impeller With its Vaned Diffuser: Flows Analysis

Volume 1: Turbomachinery ◽

10.1115/94-gt-105 ◽

1994 ◽

Cited By ~ 8

Author(s):

W. N. Dawes

Keyword(s):

Flow Analysis ◽

Three Dimensional ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Vaned Diffuser ◽

Time Resolved ◽

High Loss ◽

Swirl Angle ◽

Unsteady Interaction ◽

Unsteady Effects

The aim of this paper is to help advance our understanding of the complex, three-dimensional, unsteady flow associated with the interaction of a splattered centrifugal impeller and its vaned diffuser. A time-resolved simulation is presented of the Krain stage performed using a time-accurate, 3D, unstructured mesh, solution-adaptive Navier-Stokes solver. The predicted flowfield, compared with experiment where available, displays a complex, unsteady interaction especially in the neighbourhood of the diffuser entry zone which experiences large periodic flow unsteadiness. Downstream of the throat, although the magnitude of this unsteadiness diminishes rapidly, the flow has a highly distorted three-dimensional character. The loss levels in the diffuser are then investigated to try and determine how time-mean loss levels compare with the levels expected from “equivalent” steady flow analysis performed by using the circumferentially averaged exit flow from the impeller as inlet to the diffuser. It is concluded that little loss could be attributed directly to unsteady effects but rather that the principle cause of the rather high loss levels observed in the diffuser is the strong spanwise distortion in swirl angle at inlet which initiates a strong hub/comer stall.

Download Full-text

Numerical Investigation of Impeller Tip Tailoring and its Impact on Aerodynamic Design of a Centrifugal Compressor’s Impeller

Volume 2D: Turbomachinery ◽

10.1115/gt2014-25641 ◽

2014 ◽

Author(s):

Ashvin Mahajan ◽

Lieven Baert ◽

Michaël Leborgne ◽

Timothée Lonfils ◽

I. Gede Parwatha ◽

...

Keyword(s):

Design Optimization ◽

Significant Contribution ◽

Pressure Ratio ◽

Three Dimensional ◽

Flow Characteristics ◽

Aerodynamic Design ◽

High Pressure Ratio ◽

Important Improvement ◽

Geometrical Features ◽

Isentropic Efficiency

The current research focuses on the aerodynamic design of a centrifugal compressor and the effect of tip tailoring on the aerodynamic impeller efficiency. To this extent a high-fidelity multi-point design optimization process has been developed and exploited on a high pressure ratio transonic impeller. By manipulating the shape of the impeller blades and endwalls and by including advanced geometrical features such as winglets on the impeller blades, the behavior of the impeller flow has been investigated. Here, the results of three-dimensional RANS simulations with the Spalart-Allmaras turbulence model on a structured multi-block mesh is used for the evaluation of the flow characteristics. In the context of radial machines, the results of the aerodynamic design optimization show an important improvement of the impeller isentropic efficiency compared to the reference impeller, with a significant contribution from the presence of the impeller tip winglets. Furthermore, the integration of the impeller winglet has encouraged this study to provide a detailed analysis on the impeller flow structures in order to have a better understanding of the effects of tip tailoring on impeller performance.

Download Full-text