Fully Three-Dimensional Viscous Semi-Inverse Method for Subsonic Mixed-Flow and Radial Impeller Design

2009 ◽  
Author(s):  
Min Ji ◽  
T. Q. Dang ◽  
Michael J. Cave
Keyword(s):  
Boundary Condition ◽  
Inverse Method ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Navier Stokes ◽  
Mixed Flow ◽  
Surface Design ◽  
Geometrical Constraints ◽  
Inverse Design Method

A new semi-inverse design method for turbomachinery blading is proposed in this paper. Built on a time-marching Reynolds-Averaged Navier-Stokes solver, the proposed design method takes pressure loading, blade tangential thickness, blade stacking line, and flow path contour as prescribed quantities and computes the corresponding three-dimensional blade camber surface. In order to have the option of imposing geometrical constraints on the designed blade shapes, a new algorithm is developed to solve the camber surface at specified spanwise grid-lines, after which the blade geometry is constructed through ruling (e.g. straight-line element) at the remaining spanwise stations. The new semi-inverse algorithm involves re-formulating the boundary condition on the blade surfaces as a hybrid inverse/analysis boundary condition while preserving the fully three-dimensional nature of the flow field. The new design method can be interpreted as a fully three-dimensional viscous semi-inverse method. The ruled camber surface design procedure ensures blade surface smoothness and some control of mechanical integrity, and results in cost reduction for the manufacturing process. The proposed fully three-dimensional semi-inverse method is demonstrated through design modifications of generic industrial mixed-flow and radial impellers which are typically used for gas process applications.

Hydrodynamic Design of Pump Diffuser Using Inverse Design Method and CFD

2002 ◽  
Vol 124 (2) ◽  
pp. 319-328 ◽  
Author(s):  
Akira Goto ◽  
Mehrdad Zangeneh
Keyword(s):  
Design Method ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Inverse Design ◽  
Navier Stokes ◽  
Outer Diameter ◽  
Large Area ◽  
Suction Surface ◽  
Pump Stage ◽  
Inverse Design Method

A new approach to optimizing a pump diffuser is presented, based on a three-dimensional inverse design method and a Computational Fluid Dynamics (CFD) technique. The blade shape of the diffuser was designed for a specified distribution of circulation and a given meridional geometry at a low specific speed of 0.109 (non-dimensional) or 280 (m3/min, m, rpm). To optimize the three-dimensional pressure fields and the secondary flow behavior inside the flow passage, the diffuser blade was more fore-loaded at the hub side as compared with the casing side. Numerical calculations, using a stage version of Dawes three-dimensional Navier-Stokes code, showed that such a loading distribution can suppress flow separation at the corner region between the hub and the blade suction surface, which was commonly observed with conventional designs having a compact bowl size (small outer diameter). The improvements in stage efficiency were confirmed experimentally over the corresponding conventional pump stage. The application of multi-color oil-film flow visualization confirmed that the large area of the corner separation was completely eliminated in the inverse design diffuser.

Optimization of Microturbine Aerodynamics Using CFD, Inverse Design and FEM Structural Analysis: 1st Report — Compressor Design

2004 ◽  
Author(s):  
Kosuke Ashihara ◽  
Akira Goto ◽  
Shijie Guo ◽  
Hidenobu Okamoto
Keyword(s):  
High Speed ◽  
Structural Reliability ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Inverse Design ◽  
Blade Profile ◽  
Vaned Diffuser ◽  
Performance Improvements ◽  
Inverse Design Method

In this paper, a new aerodynamic design procedure is presented for a centrifugal compressor stage of a microturbine system. To optimize the three-dimensional (3-D) flows and the performance, an inverse design method, which numerically generates the 3-D blade geometry for specified blade loading distribution, has been applied together with the numerical validation using CFD (Computational Fluid Dynamics) and FEM (Finite Element Method). The blade profile along the shroud surface of the impeller was optimized based on the 3-D inverse design and CFD. However, the blade profile towards the hub surface was modified geometrically to achieve a nearly radial blade element especially at the inducer part of the impeller, in order to meet the required structural strength. The modified impeller successfully kept similar aerodynamic performance as that of a blade with a fully 3-D shape, whilst showing improved structural reliability. So, the proposed method to adopt the blade profile designed by the inverse method along the shroud, and to geometrically modify the blade profile towards the hub, was confirmed to be effective to design a high-speed compressor impeller. The vaned diffuser has also been re-designed using the inverse design method. The corner separation in the conventional wedge-type diffuser channel was suppressed in the new design. The stage performance improvements were confirmed by stage calculations using CFD.

scholarly journals An improved inverse method for multirow blades of turbomachinery

2020 ◽  
Vol 234 (22) ◽  
pp. 4433-4443
Author(s):  
Li Aiting ◽  
Zhu Yangli ◽  
Li Wen ◽  
Wang Xing ◽  
Qin Wei ◽  
...  
Keyword(s):  
Flow Structure ◽  
Inverse Method ◽  
Design Method ◽  
Spline Interpolation ◽  
Thickness Distribution ◽  
Three Dimensional ◽  
Internal Flow ◽  
Navier Stokes ◽  
Virtual Displacement ◽  
Blade Thickness

A three-dimensional viscous inverse design method is improved and extended to multirow blades environment. The inverse method takes load distribution as optimization objective and is implemented into the time-marching finite-volume Reynolds-averaged Navier–Stokes solver. The camber line of rotor blade is updated by virtual displacement, which is calculated by characteristic compatibility relations according to the difference between target and actual load so as to control the location and intensity of shock wave, and realize the optimization of flow structure and reduction flow separation. The inlet and outlet geometry angles of stator blade are adjusted in real time according to the inlet and outlet flow angles. Thus, it is computationally ensured that the blade row interactions are accounted and optimization process is carried out under the design condition. To preserve the robustness of calculation, the maximum virtual displacement is limited by Y+ <10 and the camber line is smoothed via cubic B-spline interpolation. The complete blade profile is then generated by adding the prescribed blade thickness distribution to the camber line. The effectiveness of the method is demonstrated in the optimization of Stage35 compressor stage. Numerical results showed that this inverse method can effectively improve the internal flow structure and optimize the matching between blade rows, and this method is robust, efficient, and flexible.

A Compressible Three-Dimensional Inverse Design Method Based on the Streamline Curvature Approach and Clebsch Formulation for Radial and Mixed Flow Turbomachines

2012 ◽  
Author(s):  
Xiao Pei Tian ◽  
Peng Shan
Keyword(s):  
Flow Field ◽  
Inverse Method ◽  
Design Method ◽  
Inverse Design ◽  
Periodic Flow ◽  
Mixed Flow ◽  
3 Dimensional ◽  
Streamline Curvature ◽  
Through Flow ◽  
Inverse Design Method

The through-flow inverse design method based on the streamline curvature approach is nowadays a widely used quasi-3-dimensional blades design method for radial and mixed flow turbomachines. The main limitation of this method is using the flow field on the mean stream surface S2,m to approximate the actual 3-dimensional flow field. Without an effective description of the periodic flow, it is impossible for this method to realize exactly the prescribed circumferentially averaged swirl rVθ. Is there any way to develop this classical through-flow inverse method to a 3-dimensional one conveniently? The answer is yes. A new compressible 3-dimensional inverse design method for radial and mixed flow turbomachines is presented in this paper. This new 3-dimensional inverse method provides a convenient and effective way to obtain the periodic flow field for the streamline curvature through-flow inverse method. Meanwhile, compared with another type of similar 3-dimensional inverse method firstly described by Tan etc. based on Stokes stream functions and Monge potential functions from the Clebsch formulation to calculate the circumferentially averaged flow and the periodic flow respectively, this new method has its own advantages. In order to assess the usefulness of the new method, four centrifugal impellers are designed under the same design specifications by four different inverse methods respectively. They are two quasi-3-dimensional streamline curvature through-flow inverse methods without and with a slip factor model, a 3-dimensional approximated inverse approach based on stream functions and Monge potential functions and the 3-dimensional inverse method presented here. The performances of the four impellers yielding from a RANS commercial solver are compared. The capabilities of the four methods to realize the target circumferentially averaged swirl are also studied.

Advanced Transonic Fan Design Procedure Based on a Navier–Stokes Method

1994 ◽  
Vol 116 (2) ◽  
pp. 291-297 ◽  
Author(s):  
C. M. Rhie ◽  
R. M. Zacharias ◽  
D. E. Hobbs ◽  
K. P. Sarathy ◽  
B. P. Biederman ◽  
...  
Keyword(s):  
Stokes Equations ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Cost Savings ◽  
Inviscid Flow ◽  
Navier Stokes ◽  
Compressor Cascade ◽  
Validation Data ◽  
Navier Stokes Equations

A fan performance analysis method based upon three-dimensional steady Navier–Stokes equations is presented in this paper. Its accuracy is established through extensive code validation effort. Validation data comparisons ranging from a two-dimensional compressor cascade to three-dimensional fans are shown in this paper to highlight the accuracy and reliability of the code. The overall fan design procedure using this code is then presented. Typical results of this design process are shown for a current engine fan design. This new design method introduces a major improvement over the conventional design methods based on inviscid flow and boundary layer concepts. Using the Navier–Stokes design method, fan designers can confidently refine their designs prior to rig testing. This results in reduced rig testing and cost savings as the bulk of the iteration between design and experimental verification is transferred to an iteration between design and computational verification.

Turbomachinery Blade Design Using 3-D Inverse Design Method, CFD and Optimization Algorithm

2001 ◽  
Author(s):  
Kosuke Ashihara ◽  
Akira Goto
Keyword(s):  
Simulated Annealing ◽  
Optimization Algorithm ◽  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Mixed Flow ◽  
Specific Speed ◽  
Inverse Design Method ◽  
Suction Performance ◽  
Flow Pump

An optimization approach for improving turbomachinery performance was proposed based on a three-dimensional inverse design method, a Computational Fluid Dynamics (CDF) and optimization algorithm. By combining the three-dimensional inverse design method and CFD predictions, the blade loading parameters which is the major inputs for the three-dimensional inverse design method were treated as design variables and the impeller performance predicted by CFD was treated as an objective function of the optimization problem. Firstly, to clarify the effects of optimization algorithm, mixed-flow pump impellers (Ns400), with a specific speed of 400 (m3/min,m,min−1) or 0.155 (non-dimensional), were optimized to improve the impeller efficiency by using several optimization algorithm. From these results, it was confirmed that turbomachinery optimization using the three-dimensional inverse design method is a multi-peak problem and it is essential to use exploratory techniques such as Simulated Annealing. Then, a mixed-flow pump impeller (Ns1350), with a specific speed of 1350 (m3/min,m,min−1) or 0.523 (non-dimensional), was optimized to improve the impeller efficiency with constraints for suction performance by Simulated Annealing. Reasonably high efficiency and high suction performance were confirmed by comparing the CFD results with those for the previous design which employed manual optimization.

On the role of three-dimensional inverse design methods in turbomachinery shape optimization

1999 ◽  
Vol 213 (1) ◽  
pp. 27-42 ◽  
Author(s):  
M Zangeneh ◽  
A Goto ◽  
H Harada
Keyword(s):  
Flow Field ◽  
Inverse Method ◽  
Design Method ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Secondary Flows ◽  
Inverse Design ◽  
Vaned Diffuser ◽  
Oil Flow ◽  
Inverse Design Method

The application of a three-dimensional (3D) inverse design method in which the blade geometry is computed for a specified distribution of circulation to the design of turbomachinery blades is explored by using two examples. In the first instance the method is applied to the design of radial and mixed flow impellers to suppress secondary flows. Based on our understanding of the fluid dynamics of the flow in the impeller, simple guidelines are developed for input specification of the inverse method in order to systematically design impellers with suppressed secondary flows and a more uniform exit flow field. In the second example the method is applied to the design of a vaned diffuser. Again based on the understanding of the detailed flow field in the diffuser obtained by using 3D viscous calculations and oil flow visualizations, simple design guidelines are developed for input specification to the inverse method in order to suppress corner separation. In both cases the guidelines are verified numerically and in the case of the diffuser further experimental validation is presented.

A Fully Compressible Three Dimensional Inverse Design Method Applicable to Radial and Mixed Flow Turbomachines

1990 ◽  
Author(s):  
M. Zangeneh ◽  
W. R. Hawthrone
Keyword(s):  
High Speed ◽  
Design Method ◽  
Three Dimensional ◽  
Tangential Direction ◽  
Inverse Design ◽  
Mixed Flow ◽  
Exact Approach ◽  
Time Marching ◽  
The Difference ◽  
Inverse Design Method

A fully three dimensional compressible inverse design method for the design of radial and mixed flow machines is described. In this method the distribution of the circumferentially averaged swirl velocity, or rV¯θ on the meridional geometry of the impeller is prescribed and the corresponding blade shape is computed iteratively. Two approaches are presented for solving the compressible flow problem. In the approximate approach, the pitchwise variation in density is neglected and as a result the algorithm is simple and efficient. In the exact approach, the velocities and density are computed throughout the three dimensional flow field by employing Fast Fourier Transform in the tangential direction. The results of the approximate and exact approach are compared for the case of a high speed (subsonic) radial-inflow turbine and it is shown that the difference between the blade shapes computed by the two methods is well within the manufacturing tolerances. The flow through the designed impeller is analysed by using three dimensional inviscid and viscous time marching programs and very good correlations between the specified and computed rV¯θ is obtained.

Suppression of Secondary Flows in a Mixed-Flow Pump Impeller by Application of Three-Dimensional Inverse Design Method: Part 2—Experimental Validation

1996 ◽  
Vol 118 (3) ◽  
pp. 544-551 ◽  
Author(s):  
A. Goto ◽  
T. Takemura ◽  
M. Zangeneh
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Flow Fields ◽  
Secondary Flows ◽  
Inverse Design ◽  
Suction Surface ◽  
Mixed Flow ◽  
Pump Impeller ◽  
Inverse Design Method ◽  
Flow Pump

In Part 1 of this paper, a mixed-flow pump impeller was designed by a fully three-dimensional inverse design method, aimed at suppressing the secondary flows on the blade suction surface. In this part, the internal flow fields of the impeller are investigated experimentally, using flow visualization and phase-locked measurements of the impeller exit flow, in order to validate the effects of secondary flow suppression. The flow fields are compared with those of a conventional impeller, and it is confirmed that the secondary flows on the blade suction surface are well suppressed and the uniformity of the exit flow fields is improved substantially, in both circumferential and spanwise directions. The effects of tip clearance and the number of blades for the inverse designed impeller are also investigated experimentally and numerically.

A New Three-Dimensional Viscous Inverse Design Method for Axial Compressor Blade

2016 ◽  
Author(s):  
Zhaowei Liu ◽  
Hu Wu
Keyword(s):  
Pressure Distribution ◽  
Static Pressure ◽  
Design Method ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Design Procedure ◽  
Inverse Design ◽  
Blade Surface ◽  
Static Pressure Distribution ◽  
Inverse Design Method

A recently developed aerodynamic inverse design method for axial compressor is presented in this paper. The inverse design method is based on solving the three-dimensional Reynolds-averaged Navier-Stokes equations. Blade surface static pressure distribution is prescribed before the design procedure. A new inverse design boundary condition is established based on the conservation of Riemann invariant on the blade surface. Blade profile is constantly modified by a virtual wall velocity which is obtained from the difference between the current and prescribed static pressure. The dynamic mesh theory is used to update the computation mesh where the shape of the blade is changing during the design process. The design procedure finishes after the prescribed static pressure distribution on the blade surface is satisfied. The method is first validated by a blade recovery test. It is then used to redesign the NASA Rotor 67.

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