Redesign of Axial Fan using Viscous Inverse Design Method based on Boundary Vorticity Flux Diagnosis

2021 ◽  
pp. 1-42
Author(s):  
Hui Liu ◽  
Boyan Jiang ◽  
Wei Wang ◽  
Xiaopei Yang ◽  
Jun Wang
Keyword(s):  
Design Method ◽  
Internal Flow ◽  
Inverse Design ◽  
Pressure Loading ◽  
Axial Fan ◽  
High Quality ◽  
Wall Boundary Conditions ◽  
Aerodynamic Parameters ◽  
Inverse Design Method ◽  
Vorticity Flux

Abstract The inverse design method for turbomachinery can directly acquire a blade geometry with specific aerodynamic parameters, such as pressure loading on the blade surfaces. The difference between the inverse design and direct analysis design is that the management of the flow field is controlled by aerodynamic parameters instead of geometric parameters. Although the inverse design has been studied since the 1940s, it is far from being mature enough in comparison with the analysis method. In this work, the inverse problem method is improved by two aspects: the calculation accuracy and the strategy to determine the pressure loading distribution. The application of a high-quality mesh auto-generation and deformation technique to the inverse design is introduced. The no-slip wall boundary conditions, similar to the analysis mode, and high-quality mesh enable the use of an advanced turbulence model in the inverse design. These methods improve the accuracy of the inverse design. The loading distribution in the inverse design is obtained based on the boundary vorticity flux diagnosis. An axial fan is redesigned as an example of the inverse design method. The internal flow loss analysis based on the entropy production theory verifies the effectiveness of the inverse design used in this study.

Rotational compressible inverse design method for two-dimensional, internal flow configurations

AIAA Journal ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 551-558 ◽  
Author(s):  
V. Dedoussis ◽  
P. Chaviaropoulos ◽  
K. D. Papailiou
Keyword(s):  
Design Method ◽  
Internal Flow ◽  
Inverse Design ◽  
Two Dimensional ◽  
Flow Configurations ◽  
Inverse Design Method

On Design of Transonic Fan Rotors by 3D Inverse Design Method

2006 ◽  
Author(s):  
Peixin Hu ◽  
Mehrdad Zangeneh ◽  
Benjamin Choo ◽  
Mohammad Rahmati
Keyword(s):  
Structural Integrity ◽  
Design Method ◽  
Leading Edge ◽  
Tip Clearance ◽  
Inverse Design ◽  
Pressure Loading ◽  
Tip Clearance Flow ◽  
Blade Thickness ◽  
Inverse Design Method ◽  
Transonic Fan

The application of 3D inverse design to transonic fans can offer designers many advantages in terms of reduction in design time and providing a more direct means of using the insight obtained into flow physics from CFD computations directly in the design process. A number of papers on application of inverse design method to transonic fans have already been reported. However, in order to apply this approach in product design a number of issues need to be addressed. For example, how can the method be used to affect and control the fan rotor characteristics? The robustness of the method and its ability to deal with accurate representation of leading and trailing edges, as well as tip clearance flow. In this paper the further enhancement of the 3D viscous transonic inverse design code TURBOdesign-2 and its application to the re-design of NASA37 and NASA67 rotors will be described. In this inverse design method the blade geometry can be computed by the specification of the blade loading (meridional derivative of rVθ) or the pressure loading. In both cases the blade normal thickness is specified to ensure structural integrity of the design. Improvements to the code include implementation of full approximation storage (FAS) multigrid technique in the solver, which increases the speed of the computation. This method allows the modification of blade thickness and pressure loading by B-splines. In addition improvements have been made in the treatment of proper leading edge geometry. Two well known examples of NASA 67 and NASA 37 rotors are used to provide a step-by-step guide to the application of the method to the design of transonic fan rotors. Improved designs are validated by commercial CFD code CFX.

Development of an (Adaptive) Unstructured 2-D Inverse Design Method for Turbomachinery Blades

2002 ◽  
Author(s):  
Benjamin M. F. Choo ◽  
Mehrdad Zangeneh
Keyword(s):  
Shock Waves ◽  
Design Method ◽  
Inverse Design ◽  
Pressure Jump ◽  
Triangular Meshes ◽  
Pressure Loading ◽  
Trailing Edge ◽  
Turbomachinery Blades ◽  
Inverse Design Method ◽  
Blade Geometry

An aerodynamics inverse design method for turbomachinery blades using fully (adaptive) unstructured meshes is presented. In this design method, the pressure loading (i.e. pressure jump across the blades) and thickness distribution are prescribed. The design method then computes the blade shape that would accomplish this loading. This inverse design method is implemented using a cell-centred finite volume method which solves the Euler equations on Delaunay unstructured triangular meshes using upwind flux vector splitting scheme. The analysis/direct Euler solver first is validated against some test cases of cascades flow. Computational grid and solution adaptation is performed to capture any flow behaviors such as shock waves using some error indicators. In the inverse design method, blade geometry is updated at the end of each design iteration process. A flexible and fast remeshing process based on a classical ‘spring’ methodology is adopted. An improved spring smoothing methodology for large changes of blades geometry is also presented. This flexible remeshing method can be used in designing a real blade (i.e. round leading and trailing edge) and also ‘fat’ turbine blades with blunt leading and trailing edge. The inverse design method using unstructured triangular meshes is validated by regeneration of a generic compressor rotor blade geometry subjected to a specified pressure loading and blade thickness. Finally, the method is applied to the design of the tip section of Nasa Rotor 67. The result shows that the design method is very useful in controlling shock waves.

Redesign of a Low Speed Turbine Stage Using a New Viscous Inverse Design Method

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Benedikt Roidl ◽  
Wahid Ghaly
Keyword(s):  
Stokes Equations ◽  
Design Method ◽  
Accurate Solution ◽  
Inverse Design ◽  
Pressure Loading ◽  
Turbine Stage ◽  
Low Speed ◽  
Target Pressure ◽  
Stage Performance ◽  
Inverse Design Method

The midspan section of a low speed subsonic turbine stage that is built and tested at DFVLR, Cologne, is redesigned using a new inverse blade design method, where the blade walls move with a virtual velocity distribution derived from the difference between the current and target pressure distributions on the blade surfaces. This new inverse method is fully consistent with the viscous flow assumption and is implemented into the time-accurate solution of the Reynolds-averaged Navier–Stokes equations. An algebraic Baldwin–Lomax turbulence model is used for turbulence closure. The mixing plane approach is used to couple the stator and rotor regions. The computational fluid dynamics (CFD) analysis formulation is first assessed against the turbine stage experimental data. The inverse formulation that is implemented in the same CFD code is assessed for its robustness and merits. The inverse design method is then used to study the effect of the rotor pressure loading on the blade shape and stage performance. It is also used to simultaneously redesign both stator and rotor blades for improved stage performance. The results show that by carefully tailoring the target pressure loading on both blade rows, improvement can be achieved in the stage performance.

Redesign of a Low Speed Turbine Stage Using a New Viscous Inverse Design Method

2008 ◽  
Author(s):  
Benedikt Roidl ◽  
Wahid Ghaly
Keyword(s):  
Stokes Equations ◽  
Design Method ◽  
Accurate Solution ◽  
Inverse Design ◽  
Pressure Loading ◽  
Turbine Stage ◽  
Low Speed ◽  
Target Pressure ◽  
Stage Performance ◽  
Inverse Design Method

The midspan section of a low speed subsonic turbine stage that is built and tested at DFVLR, Cologne, is redesigned using a new inverse blade design method where the blade walls move with a virtual velocity distribution derived from the difference between the current and the target pressure distributions on the blade surfaces. This new inverse method is fully consistent with the viscous flow assumption and is implemented into the time accurate solution of the Reynolds-Averaged Navier-Stokes equations. An algebraic Baldwin-Lomax turbulence model is used for turbulence closure. The mixing plane approach is used to couple the stator and the rotor regions. The CFD analysis formulation is first assessed against the turbine stage experimental data. The inverse formulation that is implemented in the same CFD code is also assessed for its robustness and merits. The inverse design method is then used to study the effect of the rotor pressure loading on the blade shape and stage performance. It is also used to simultaneously redesign both stator and rotor blades for improved stage performance. The results show that by carefully tailoring the target pressure loading on both blade rows, improvement can be achieved in the stage performance.

Influence of Spanwise Distribution of Impeller Exit Circulation on Optimization Results of Mixed Flow Pump

2021 ◽  
Vol 11 (2) ◽  
pp. 507
Author(s):  
Mengcheng Wang ◽  
Yanjun Li ◽  
Jianping Yuan ◽  
Fareed Konadu Osman
Keyword(s):  
Design Method ◽  
Internal Flow ◽  
Inverse Design ◽  
Pump Efficiency ◽  
Mixed Flow ◽  
Baseline Model ◽  
Pump Impeller ◽  
First Case ◽  
Inverse Design Method ◽  
Flow Pump

The spanwise distribution of impeller exit circulation (SDIEC) has an important influence on the performance of the impeller. To quantitatively study the influence of SDIEC on optimization results, a comprehensive optimization system composed of the computational fluid dynamics, inverse design method, design of experiment, surrogate model, and optimization algorithm was used to optimize a mixed flow pump impeller in two different cases. In the first case, the influence of SDIEC was ignored, while in the second case, the influence of SDIEC was considered. The result shows that the optimization upper limit can be further improved when the influence of SDIEC is considered in the optimization process. The pump efficiency of the preferred optimized impeller F1 obtained in the first case at 1.2Qdes, 1.0Qdes, and 0.8Qdes are increased by 6.48%, 2.41%, and 0.06%, respectively, over the baseline model. Moreover, the pump efficiency of the preferred optimized impeller S2 obtained in the second case further increased by 0.76%, 1.24%, and 1.21%, respectively, over impeller F1. Furthermore, the influence of SDIEC on the performance of the mixed flow pump is clarified by a comparative analysis of the internal flow field.

Design of axial fan using inverse design method

2008 ◽  
Vol 22 (10) ◽  
pp. 1883-1888 ◽  
Author(s):  
Kyoung-Yong Lee ◽  
Young-Seok Choi ◽  
Young-Lyul Kim ◽  
Jae-Ho Yun
Keyword(s):  
Design Method ◽  
Inverse Design ◽  
Axial Fan ◽  
Inverse Design Method

A Novel 2D Incompressible Viscous Inverse Design Method for Internal Flows Using Flexible String Algorithm

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Mahdi Nili-Ahmadabadi ◽  
Ali Hajilouy-Benisi ◽  
Farhad Ghadak ◽  
Mohammad Durali
Keyword(s):  
Compressible Flows ◽  
Design Method ◽  
Flow Analysis ◽  
Internal Flow ◽  
Separated Flow ◽  
Inverse Design ◽  
Design Algorithm ◽  
String Algorithm ◽  
The Difference ◽  
Inverse Design Method

In this investigation, the flexible string algorithm (FSA), used before for inverse design of subsonic and supersonic ducts in compressible flows with and without normal shock, is developed and applied for inverse design of 2D incompressible viscous internal flow with and without separation. In the proposed method, the duct wall shape is changed under an algorithm based on deformation of a virtual flexible string in flow. At each modification step, the difference between current and target wall pressure distributions is applied to the string. The method is an iterative inverse design method and utilizes the analysis code for the flow field solution as a black-box. Some validation test cases and design examples are presented here, which show the robustness and flexibility of the method in handling complex geometries. In cases with separated flow pressure distribution, a unique solution for inverse design problem does not exist. The design algorithm is a physical and quick converging approach and can efficiently utilize commercial flow analysis software.

Enhanced Blade Row Matching Capabilities via 3D Multistage Inverse Design and Pressure Loading Manager

2008 ◽  
Author(s):  
M. P. C. van Rooij ◽  
T. Q. Dang ◽  
L. M. Larosiliere
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Careful Examination ◽  
Pressure Loading ◽  
Design Quality ◽  
Flow Angle ◽  
Transonic Compressor ◽  
Point Control ◽  
Inverse Design Method

Three-dimensional inverse design has become a reliable and powerful tool for facilitating the refinement of blading designs. Its main strength lies in the direct control offered over local aerodynamics and, when the method is based on pressure loading, net circulation. While the ability to specify pressure loading offers many advantages, it is often not obvious to a designer what loading distribution should be prescribed. Not only should a suitable blade shape be achieved, but also satisfactory performance and design constraints such as mass flow, exit flow angle distributions and compression ratio. This problem is exacerbated when applying inverse design in a multistage environment, where interactions between blade rows affect the design and the resulting flow field in ways that are often intractable. Thus, numerous revisions of the prescribed loading, with a careful examination of how changes to the prescribed loading influence the resulting design, can still be necessary before obtaining a satisfactory design. A pressure loading manager has been developed to alleviate these problems. This loading manager can automatically adjust pressure loading distributions during the inverse design process to achieve greater control over the aerodynamic design intent. In combination with a fully three-dimensional multistage viscous inverse design method, a powerful method for blading revision is obtained that offers enhanced aerodynamic matching capabilities and design point control. Increased aero-design quality and productivity in difficult design situations can be achieved. This is demonstrated with the redesign of a highly loaded 2.5-stage transonic compressor.

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