An Inverse Design Based Methodology for Rapid 3D Multi-Objective/Multidisciplinary Optimization of Axial Turbines

2011 ◽  
Author(s):  
Pietro Boselli ◽  
Mehrdad Zangeneh
Keyword(s):  
Design Method ◽  
Turbine Blades ◽  
Multidisciplinary Optimization ◽  
Inverse Design ◽  
Design Parameters ◽  
Multi Objective ◽  
Work Distribution ◽  
Blade Shape ◽  
Inverse Design Method ◽  
Axial Turbines

Design of axial turbines, especially LP turbines, poses difficult tradeoffs between requirements of aerodynamic design and structural limitations. In this paper, a methodology is proposed for 3D multi-objective design of axial turbine blades in which a 3D inverse design method is coupled with a multi-objective genetic algorithm. By parameterizing the blade using blade loading parameters, spanwise work distribution and maximum thickness, a large part of the design space can be explored with very few design parameters. Furthermore, the inverse method not only computes the blade shape but also provides accurate 3D inviscid flow information. In the simple multi-disciplinary approach proposed here the different losses in axial turbines such as endwall losses, tip leakage losses and an indication of flow separation are related through well known correlations to the blade surface velocities predicted by the inverse design method. In addition, geometrical features such as throat area, lean angles and airfoil cross sectional area are computed from the blade shape employed during the optimization. Also, centrifugal stresses and bending stresses are related to the blade geometry. The methodology is then applied to the redesign of an LP turbine rotor with the aim of reducing the maximum stresses while maintaining the performance of the rotor. The results are confirmed by using the commercial CFX CFD (Computational Fluid Dynamics) code and Ansys FEA (Finite Element Analysis) codes.

scholarly journals Multi-Objective Optimization of a High Specific Speed Centrifugal Volute Pump Using 3D Inverse Design Coupled With CFD Simulations

2019 ◽  
Author(s):  
Luying Zhang ◽  
Gabriel Davila ◽  
Mehrdad Zangeneh
Keyword(s):  
Surrogate Model ◽  
Design Method ◽  
Inverse Design ◽  
Multi Objective Optimization ◽  
Blade Angle ◽  
Multi Objective ◽  
Specific Speed ◽  
Meridional Shape ◽  
Inverse Design Method ◽  
Conventional Optimization

Abstract This paper presents three different multi-objective optimization strategies for a high specific speed centrifugal volute pump design. The objectives of the optimization consist of maximizing the efficiency and minimizing the cavitation while maintaining the Euler head. The first two optimization strategies use a 3D inverse design method to parametrize the blade geometry. Both meridional shape and 3D blade geometry is changed during the optimization. In the first approach Design of Experiment method is used and the efficiency computed from CFD computations, while cavitation is evaluated by using minimum pressure on blade surface predicted by 3D inverse design method. The design matrix is then used to create a surrogate model where optimization is run to find the best tradeoff between cavitation and efficiency. This optimized geometry is manufactured and tested and is found to be 3.9% more efficient than the baseline with little cavitation at high flow. In the second approach the 3D inverse design method output is used to compute the efficiency and cavitation parameters and this leads to considerable reduction to the computational time. The resulting optimized geometry is found to be similar to the more computationally expensive solution based on 3D CFD results. In order to compare the inverse design based optimization to the conventional optimization an equivalent optimization is carried out by parametrizing the blade angle and meridional shape. Two different approaches are used for conventional optimization one in which the blade angle at TE is not constrained and one in which blade angles are constrained. In both cases larger variation in head is obtained when compared with the inverse design approach. This makes it impossible to create an accurate surrogate model. Furthermore, the efficiency levels in the conventional optimization is generally lower than the inverse design based optimization.

scholarly journals Three-Dimensional Inverse Design Method for Hydraulic Machinery

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3210
Author(s):  
Wei Yang ◽  
Benqing Liu ◽  
Ruofu Xiao
Keyword(s):  
High Performance ◽  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Blade Loading ◽  
Hydraulic Machinery ◽  
Main Challenge ◽  
Blade Shape ◽  
Stacking Condition ◽  
Inverse Design Method

Hydraulic machinery with high performance is of great significance for energy saving. Its design is a very challenging job for designers, and the inverse design method is a competitive way to do the job. The three-dimensional inverse design method and its applications to hydraulic machinery are herein reviewed. The flow is calculated based on potential flow theory, and the blade shape is calculated based on flow-tangency condition according to the calculated flow velocity. We also explain flow control theory by suppression of secondary flow and cavitation based on careful tailoring of the blade loading distribution and stacking condition in the inverse design of hydraulic machinery. Suggestions about the main challenge and future prospective of the inverse design method are given.

A Novel Two Dimensional Viscous Inverse Design Method for Turbomachinery Blading

2002 ◽  
Author(s):  
L. de Vito ◽  
R. A. Van den Braembussche ◽  
H. Deconinck
Keyword(s):  
Pressure Distribution ◽  
Design Method ◽  
Turbine Blades ◽  
Inverse Design ◽  
Navier Stokes ◽  
Particular Solution ◽  
Target Pressure ◽  
Inverse Design Method ◽  
Euler Solver ◽  
Stagger Angle

This paper presents a novel iterative viscous inverse method for turbomachinery blading design. It is made up of two steps: The first one consists of an analysis by means of a Navier-Stokes solver, the second one is an inverse design by means of an Euler solver. The inverse design resorts to the concept of permeable wall, and recycles the ingredients of Demeulenaere’s inviscid inverse design method that was proven fast and robust. The re-design of the LS89 turbine nozzle blade, starting from different arbitrary profiles at subsonic and transonic flow regimes, demonstrates the merits of this approach. The method may result in more than one blade profile that meets the objective, i.e. that produces the viscous target pressure distribution. To select one particular solution among all candidates, a target mass flow is enforced by adjusting the outlet static pressure. The resulting profiles are smooth (oscillation-free). The design of turbine blades with arbitrary pressure distribution at transonic and supersonic outflow illustrates the correct behavior of the method for a large range of applications. The approach is flexible because only the pitch chord ratio is fixed and no limitations are imposed on the stagger angle.

A Fast 3D Inverse Design Based Multi-Objective Optimization Strategy for Design of Pumps

2009 ◽  
Author(s):  
M. Zangeneh ◽  
K. Daneshkhah
Keyword(s):  
Pareto Front ◽  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Design Parameters ◽  
Optimization Strategy ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Pump Stage ◽  
Meridional Shape

A methodology for designing pumps to meet multi-objective design criteria is presented. The method combines a 3D inviscid inverse design method with a multi-objective genetic algorithm to design pumps which meet various aerodynamic and geometrical requirements. The parameterization of the blade shape through the blade loading enables 3D optimization with very few design parameters. A generic pump stage is used to demonstrate the proposed methodology. The main design objectives are improving cavitation performance and reducing leading edge sweep. The optimization is performed subject to certain constraints on Euler head, throat area, thickness and meridional shape so that the resulting pump can meet both design and off-design conditions. A Pareto Front is generated for the two objective functions and 3 different configurations on the Pareto front are selected for detailed study by 3D RANS code. The CFD results confirm the main outcomes of the optimization process.

Redesign of a Transonic Compressor Rotor by Means of a Three-Dimensional Inverse Design Method: A Parametric Study

2007 ◽  
Author(s):  
Duccio Bonaiuti ◽  
Abeetha Pitigala ◽  
Mehrdad Zangeneh ◽  
Yansheng Li
Keyword(s):  
Design Method ◽  
Thickness Distribution ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Inverse Design ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Blade Loading ◽  
Inverse Design Method ◽  
The Impact

In the present paper, the redesign of a transonic rotor was performed by means of a three-dimensional viscous inverse design method. The inverse approach used in this work is one where the pressure loading, blade thickness distribution and stacking axis are specified and the camber surface is calculated accordingly. The design of transonic and supersonic axial compressors strongly relies on the ability to control the shock strength, location and structure. The use of an inverse design method allows one to act directly on aerodynamic parameters, like the blade loading, and provides an efficient tool to control the shock wave and its interaction with the boundary and secondary flows and with the tip clearance vortex. In the present study, the parametric investigation of the blade loading distribution was carried out. Few design parameters, with immediate physical meaning, were required to control the three-dimensional blade loading, and their impact on the design and off-design performance of the rotor was assessed by means of CFD calculations. Further investigations were then performed in order to study the impact on the rotor performance of the geometrical parameters (meridional channel and thickness distribution), which must be imposed in the design with the inverse method. As a result, it was possible to develop guidelines for the aerodynamic design of transonic rotors that can be exploited for similar design applications.

An Inverse-Design Method for Centrifugal Pump Impellers

2005 ◽  
Author(s):  
R. W. Westra ◽  
N. P. Kruyt ◽  
H. W. M. Hoeijmakers
Keyword(s):  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Centrifugal Pumps ◽  
The Finite Element Method ◽  
Main Design ◽  
Blade Shape ◽  
The Mean ◽  
Inverse Design Method ◽  
Main Design Parameter

The development of an inverse-design method for the impellers of centrifugal pumps is presented. The flow inside the impeller channel is assumed to be irrotational, inviscid and incompressible. With the inverse-design method infinitely-thin impeller blades can be designed for a given meridional geometry and design conditions. The main design parameter is the mean-swirl distribution, which is specified from leading edge to trailing edge and from hub to shroud. The flow in the impeller channel is solved using the Finite Element Method, employing the mean-swirl distribution as a boundary condition. The blade shape is changed iteratively until the blade impenetrability condition is fulfilled. The method has been verified by considering a case for which an analytical solution is available and by reconstruction of an existing geometry, with known characteristics, using the inverse-design method. As an application of the method a mixed-flow impeller has been designed and the effect of changing the mean-swirl distribution on the resulting blade shape is clearly demonstrated.

Suppression of Secondary Flows in a Turbine Nozzle With Controlled Stacking Shape and Exit Circulation by 3D Inverse Design Method

1999 ◽  
Author(s):  
H. Watanabe ◽  
H. Harada
Keyword(s):  
Nozzle Exit ◽  
Inverse Method ◽  
Design Method ◽  
Secondary Flows ◽  
Inverse Design ◽  
Turbine Stage ◽  
Axial Turbine ◽  
Work Distribution ◽  
Inverse Design Method ◽  
3D Stacking

For the axial turbine stage, the design of circulation rVθ¯ distribution between the nozzle and blade has an important effect on the stage performance, because it determines the work distribution in the blade, the stage reaction and the twisting shape of the blade. This paper describes the new method of full 3D design for axial turbine nozzles and blades by applying the 3D inverse design method in which the blade geometry can be determined by specified distributions of circulation rVθ¯ and blade thickness. In this 3D inverse design method, spanwise work distribution of the turbine stage is controlled by specifying the rVθ¯ distribution of the nozzle exit. In this design procedure, rVθ¯ distribution at the nozzle exit and 3D stacking condition are both controlled by 3D inverse method so as to suppress the nozzle secondary flows effectively. The desirable rVθ¯ distribution and 3D stacking shape which were obtained by the 3D inverse method were confirmed by Dawes’ 3D Navier-Stokes analysis. The results shows that the secondary loss is reduced when the design rVθ¯ at the mid-span is set larger compared to that near the endwall. In addition to the control of the rVθ¯ distribution, 3D stacking shape added only in the front part of the nozzle is very effective to suppress the secondary flows, although this 3D stacking shape is very simple compared to a conventional bowed type stacking. Moreover, when this stacking shape is used, spanwise distribution of work does not change from the design condition unlike the case of conventional bowed type stacking shape. The results of single stage performance test conducted using an air turbine facility show an improvement in efficiency compared to the 2D designed stage and prove viability of the 30 inverse design of axial turbine blades.

scholarly journals On 3D Inverse Design of Centrifugal Compressor Impellers With Splitter Blades

1998 ◽  
Author(s):  
M. Zangeneh
Keyword(s):  
Centrifugal Compressor ◽  
Design Methodology ◽  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Conventional Design ◽  
Blade Shape ◽  
Edge Location ◽  
Stacking Condition ◽  
Inverse Design Method

In the design of centrifugal compressor impellers with splitter blades it is quite common to use the same blade shapes on the full and splitter blades with the splitters placed at the mid-pitch location. However, recent results using conventional design methodology have indicated that by moving the pitchwise location of the leading edge of the splitter it is possible to improve splitter performance. In this paper a 3D inverse design method is developed for the design of compressor impellers with splitters. In this design method the blades are designed subject to a specified distribution of the circulation on the full and splitter blades. The paper describes the choice of loading (or derivative of circulation with respect to meridional distance) and stacking condition to limit the complexity of the blade shape. Two different generic impellers are designed with different splitter leading edge location. The performance of these inverse designed impellers is then compared with the corresponding conventional impellers by using a 3D viscous code at design and off-design conditions.

A Novel Two-Dimensional Viscous Inverse Design Method for Turbomachinery Blading

2003 ◽  
Vol 125 (2) ◽  
pp. 310-316 ◽  
Author(s):  
L. de Vito ◽  
R. A. Van den Braembussche ◽  
H. Deconinck
Keyword(s):  
Pressure Distribution ◽  
Design Method ◽  
Turbine Blades ◽  
Inverse Design ◽  
Navier Stokes ◽  
Particular Solution ◽  
Target Pressure ◽  
Inverse Design Method ◽  
Euler Solver ◽  
Stagger Angle

This paper presents a novel iterative viscous inverse design method for turbomachinery blading. It is made up of two steps: the first one consists of an analysis by means of a Navier-Stokes solver; the second one is an inverse design by means of an Euler solver. The inverse design resorts to the concept of permeable wall, and recycles the ingredients of Demeulenaere’s inviscid inverse design method that was proven fast and robust. The re-design of the LS89 turbine nozzle blade, starting from different arbitrary profiles at subsonic and transonic flow regimes, demonstrates the merits of this approach. The method may result in more than one blade profile that meets the objective, i.e., that produces the viscous target pressure distribution. To select one particular solution among all candidates, a target mass flow is enforced by adjusting the outlet static pressure. The resulting profiles are smooth (oscillation-free). The design of turbine blades with arbitrary pressure distribution at transonic and supersonic outflow illustrates the correct behavior of the method for a large range of applications. The approach is flexible because only the pitch chord ratio is fixed and no limitations are imposed on the stagger angle.

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