Optimization of 6.2:1 Pressure Ratio Centrifugal Compressor Impeller by 3D Inverse Design

2011 ◽  
Author(s):  
M. Zangeneh ◽  
N. Amarel ◽  
K. Daneshkhah ◽  
H. Krain
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Mechanical Performance ◽  
Design Method ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Inverse Design ◽  
Transonic Compressor ◽  
Design Variables ◽  
Compressor Impeller

In this work, the redesign of a centrifugal transonic compressor impeller with splitter blades by means of the three-dimensional inverse design code TURBOdesign-1 is presented. The basic design methodology for impellers with splitter blades is outlined and is applied in a systematic way to improve the aero/mechanical performance of a transonic 6.2:1 pressure ratio centrifugal compressor impeller. The primary design variables are the main and splitter blades loading and their thickness distributions, the splitter to main blade work ratio, as well as the span-wise swirl distribution. The flow in the original and redesigned impellers are then analyzed by means of a commercial CFD code (ANSYS CFX). The predicted flow field for the original impeller is compared with detailed L2F measurements inside and outside the impeller. The validated CFD results are used to compare the flow field in the optimized and original impeller. It is shown that the inverse design method could be effectively used to control the position and strength of the shock waves, eliminate flow separation and hence obtain a more uniform impeller exit flow in order to improve the aerodynamic performance. In addition, some results are presented on the comparison of stress and vibration in both impellers.

Inverse Design of Centrifugal Compressor Vaned Diffusers in Inlet Shear Flows

1996 ◽  
Vol 118 (2) ◽  
pp. 385-393 ◽  
Author(s):  
M. Zangeneh
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Design Method ◽  
Three Dimensional ◽  
Internal Flow ◽  
Inviscid Flow ◽  
Inverse Design ◽  
Flow Conditions ◽  
Inlet Flow ◽  
Blade Thickness

A three-dimensional inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects are modeled in the design method by using the so-called “Secondary Flow Approximation” in which the Bernoulli surfaces are convected by the tangentially mean inviscid flow field. The difference between the vane geometry of the uniform inlet flow and nonuniform inlet flow diffusers is found to be most significant from 50 percent chord to the trailing edge region. The flows through both diffusers are computed by using Denton’s three-dimensional inviscid Euler solver and Dawes’ three-dimensional Navier–Stokes solver under sheared in-flow conditions. The predictions indicate improved pressure recovery and internal flow field for the diffuser designed for shear inlet flow conditions.

Investigation of Unsteady Flow Field in a Vaned Diffuser of a Transonic Centrifugal Compressor

2006 ◽  
Vol 129 (4) ◽  
pp. 686-693 ◽  
Author(s):  
Seiichi Ibaraki ◽  
Tetsuya Matsuo ◽  
Takao Yokoyama
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Measurements ◽  
Vaned Diffuser ◽  
Transonic Compressor ◽  
Inlet Conditions

Transonic centrifugal compressors are used with high-load turbochargers and turboshaft engines. These compressors usually have a vaned diffuser to increase the efficiency and the pressure ratio. To improve the performance of such a centrifugal compressor, it is required to optimize not only the impeller but also the diffuser. However the flow field of the diffuser is quite complex and unsteady because of the impeller located upstream. Although some research on vaned diffusers has been published, the diffuser flow is strongly dependent on the particular impeller exit flow, and some of the flow physics remain to be elucidated. In the research reported here, detailed flow measurements within a vaned diffuser were conducted using a particle image velocimetery (PIV). The vaned diffuser was designed with high subsonic inlet conditions marked by an inlet Mach number of 0.95 for the transonic compressor. As a result, a complex three-dimensional flow with distortion between the shroud and the hub was observed. Also, unsteady flow accompanying the inflow of the impeller wake was confirmed. Steady computational flow analysis was performed and compared with the experimental results.

Investigation of Unsteady Flow Field in Vaned Diffuser of a Transonic Centrifugal Compressor

2006 ◽  
Author(s):  
Seiichi Ibaraki ◽  
Tetsuya Matsuo ◽  
Takao Yokoyama
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Measurements ◽  
Vaned Diffuser ◽  
Transonic Compressor ◽  
Inlet Conditions

Transonic centrifugal compressors are used with high-load turbochargers and turboshaft engines. These compressors usually have a vaned diffuser to increase the efficiency and the pressure ratio. To improve the performance of such a centrifugal compressor, it is required to optimize not only the impeller but also the diffuser. However the flow field of the diffuser is quite complex and unsteady because of the impeller located upstream. Although some research on vaned diffusers has been published, the diffuser flow is strongly dependent on the particular impeller exit flow, and some of the flow physics remain to be elucidated. In the research reported here, detailed flow measurements within a vaned diffuser were conducted using a particle image velocimetery (PIV). The vaned diffuser was designed with high subsonic inlet conditions marked by an inlet Mach number of 0.95 for the transonic compressor. As a result, a complex three-dimensional flow with distortion between the shroud and the hub was observed. Also, unsteady flow accompanying the inflow of the impeller wake was confirmed. Steady computational flow analysis was performed and compared with the experimental results.

Inverse Design of 3D Multi-Stage Transonic Fans at Dual Operating Points

2013 ◽  
Author(s):  
James H. Page ◽  
Paul Hield ◽  
Paul G. Tucker
Keyword(s):  
Design Method ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Inverse Design ◽  
Flow Angle ◽  
Trade Offs ◽  
Multi Stage ◽  
Full Speed ◽  
Computational Fluid Dynamics Cfd ◽  
Operating Points

Semi-inverse design is the automatic re-cambering of an aerofoil, during a computational fluid dynamics (CFD) calculation, in order to achieve a target lift distribution while maintaining thickness, hence “semi-inverse”. In this design method, the streamwise distribution of curvature is replaced by a stream-wise distribution of lift. The authors have developed an inverse design code based on the method of Hield (2008) which can rapidly design three-dimensional fan blades in a multi-stage environment. The algorithm uses an inner loop to design to radially varying target lift distributions, an outer loop to achieve radial distributions of stage pressure ratio and exit flow angle, and a choked nozzle to set design mass flow. The code is easily wrapped around any CFD solver. In this paper, we describe a novel algorithm for designing simultaneously for specified performance at full speed and peak efficiency at part speed, without trade-offs between the targets at each of the two operating points. We also introduce a novel adaptive target lift distribution which automatically develops discontinuous changes of calculated magnitude, based on the passage shock, eliminating erroneous lift demands in the shock vicinity and maintaining a smooth aerofoil.

Investigation of an Inversely Designed Centrifugal Compressor Stage: Part 1 — Design and Numerical Verification

2003 ◽  
Author(s):  
M. Zangeneh ◽  
M. Schleer ◽  
F. Plo̸ger ◽  
S. S. Hong ◽  
C. Roduner ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Numerical Verification ◽  
Appreciable Effect ◽  
Tip Leakage Flow ◽  
Flow Angle ◽  
Compressor Impeller ◽  
Blade Geometry

In this paper the 3D 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 mis-match 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 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 2 of the paper.

scholarly journals Optimal Design of a Centrifugal Compressor Impeller Using Evolutionary Algorithms

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Soo-Yong Cho ◽  
Kook-Young Ahn ◽  
Young-Duk Lee ◽  
Young-Cheol Kim
Keyword(s):  
Centrifugal Compressor ◽  
Optimization Algorithm ◽  
Pressure Ratio ◽  
Optimization Technique ◽  
Computational Time ◽  
Impeller Blade ◽  
Design Variables ◽  
Compressor Impeller ◽  
Artificial Neural Network Ann ◽  
Geometric Variation

An optimization study was conducted on a centrifugal compressor. Eight design variables were chosen from the control points for the Bezier curves which widely influenced the geometric variation; four design variables were selected to optimize the flow passage between the hub and the shroud, and other four design variables were used to improve the performance of the impeller blade. As an optimization algorithm, an artificial neural network (ANN) was adopted. Initially, the design of experiments was applied to set up the initial data space of the ANN, which was improved during the optimization process using a genetic algorithm. If a result of the ANN reached a higher level, that result was re-calculated by computational fluid dynamics (CFD) and was applied to develop a new ANN. The prediction difference between the ANN and CFD was consequently less than 1% after the 6th generation. Using this optimization technique, the computational time for the optimization was greatly reduced and the accuracy of the optimization algorithm was increased. The efficiency was improved by 1.4% without losing the pressure ratio, and Pareto-optimal solutions of the efficiency versus the pressure ratio were obtained through the 21st generation.

scholarly journals Research on the Simplified Design of a Centrifugal Compressor Impeller Based on Meridional Plane Modification

2018 ◽  
Vol 8 (8) ◽  
pp. 1339 ◽  
Author(s):  
Hong Xie ◽  
Moru Song ◽  
XiaoLan Liu ◽  
Bo Yang ◽  
Chuangang Gu
Keyword(s):  
Centrifugal Compressor ◽  
Design Method ◽  
Pressure Ratio ◽  
Aerodynamic Characteristics ◽  
Low Flow ◽  
Measure Data ◽  
Meridional Plane ◽  
Stall Margin ◽  
Numerical Result ◽  
Compressor Impeller

This study mainly focuses on investigating the influence of meridional contour of a steam centrifugal compressor on aerodynamic performance. An optimal design method is put forwards, in which the hub-line on the meridional plane is modified and optimized. Based on the data from numerical simulation, aerodynamic characteristics are compared in detail among a prototype and three modified impellers. It is shown that stall margin of the optimized impeller can be enlarged by approximately 50%, though at design point efficiency and pressure ratio is decreased a little bit. Under the working conditions with low flow rate, the optimized impeller exhibits the best performance compared with the prototype and two other impellers. Furthermore, numerical result is validated by the experiment and is matched the measure data very well.

Investigation of an innovative non-free vortex aerodynamic procedure to design a single-stage transonic compressor

2017 ◽  
Vol 232 (11) ◽  
pp. 2132-2143 ◽  
Author(s):  
A Shahsavari ◽  
M Nili-Ahmadabadi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Stokes Equations ◽  
Design Method ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Rotor Blades ◽  
Meridional Plane ◽  
Transonic Compressor ◽  
Performance Map

This paper presents an innovative design method for a transonic compressor based on the radial equilibrium theory by means of increasing blade loading. Firstly, the rotor blade of a transonic compressor is redesigned based on the constant spanwise de-Haller number and diffusion. The design method leads to an unconventional increased axial velocity distribution in tip section, which originates from non-uniform enthalpy distribution assumption. A code is applied to extract the compressor meridional plane and blade-to-blade geometry containing rotor and stator in order to design the blade three-dimensional view. A structured grid is generated for the numerical domain of fluid. Finer grids are used for the regions near walls to capture the boundary layer effects and behavior. Reynolds-averaged Navier–Stokes equations are solved by finite volume method for rotating zones (rotor) and stationary zones (stator). The experimental data, available for the performance map of NASA Rotor67, is used to validate the results of the current simulations. Then, the capability of the design method is validated by computational fluid dynamics that is capable of predicting the performance map. The numerical results of the new geometry by representing 11% improvement in efficiency and 19% in total pressure ratio verify the new method advantages. The computational fluid dynamics results also show that the newly designed rotor blades due to a higher velocity in the tip section have a special capacity to increase the loading without any separation. The mass flow reduction is observed in the new geometry, which could be easily improved by changing stagger angle.

On the Design Criteria for Suppression of Secondary Flows in Centrifugal and Mixed Flow Impellers

1998 ◽  
Vol 120 (4) ◽  
pp. 723-735 ◽  
Author(s):  
M. Zangeneh ◽  
A. Goto ◽  
H. Harada
Keyword(s):  
Flow Field ◽  
Pressure Distribution ◽  
Centrifugal Compressor ◽  
Design Method ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Secondary Flows ◽  
Mixed Flow ◽  
Optimum Pressure ◽  
Specific Speed

In this paper, for the first time, a set of guidelines is presented for the systematic design of mixed flow and centrifugal compressors and pumps with suppressed secondary flows and a uniform exit flow field. The paper describes the shape of the optimum pressure distribution for the suppression of secondary flows in the impeller with reference to classical secondary flow theory. The feasibility of achieving this pressure distribution is then demonstrated by deriving guidelines for the design specifications of a three-dimensional inverse design method, in which the blades are designed subject to a specified circulation distribution or 2πrVθ. The guidelines will define the optimum choice of the blade loading or ∂rVθ/∂m and the stacking condition for the blades. These guidelines are then used in the design of three different low specific speed centrifugal pump impellers and a high specific speed industrial centrifugal compressor impellers. The flows through all the designed impellers are computed numerically by a three-dimensional viscous code and the resulting flow field is compared to that obtained in the corresponding conventional impeller. The results show consistent suppression of secondary flows in all cases. The design guidelines are validated experimentally by comparing the performance of the inverse designed centrifugal compressor impeller with the corresponding conventional impeller. The overall performance of the stage with the inverse designed impeller with suppressed secondary flows was found to be 5 percent higher than the conventional impeller at the peak efficiency point. Exit flow traverse results at the impeller exit indicate a more uniform exit flow than that measured at the exit from the conventional impeller.

Experimental and Numerical Investigation of a Centrifugal Compressor and Numerical Study of the Area Ratio and Tip Clearance Effects on the Performance Characteristic

2008 ◽  
Author(s):  
Mahdi Nili-Ahmadabadi ◽  
Ali Hajilouy-Benisi ◽  
Mohammad Durali ◽  
Sayyed Mostafa Motavalli
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Area Ratio ◽  
Tip Clearance ◽  
Performance Characteristics ◽  
Navier Stokes ◽  
Sst Turbulence Model

In this research, the centrifugal compressor of a turbocharger is investigated experimentally and numerically. Performance characteristics of the compressor were obtained experimentally by measurements of rotor speed and flow parameters at the inlet and outlet of the compressor. Three dimensional flow field in the impeller and diffuser was analyzed numerically using a full Navier-Stokes program with SST turbulence model. The performance characteristics of the compressor were obtained numerically, which were then compared with the experimental results. The comparison shows good agreement. Furthermore, the effect of area ratio and tip clearance on the performance parameters and flow field was studied numerically. The impeller area ratio was changed by cutting the impeller exit axial width from an initial value of 4.1 mm to a final value of 5.1 mm, resulting in an area ratio from 0.792 to 0.965. For the rotor with exit axial width of 4.6 mm, performance was investigated for tip clearance of 0.0, 0.5 and 1.0 mm. Results of this simulation at design point showed that the compressor pressure ratio peaked at an area ratio of 0.792 while the efficiency peaked at a higher value of area ratio of 0.878. Also the increment of the tip clearance from 0 to 1 mm resulted in 20 percent efficiency decrease.

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