Turbine Blade Duty Re-Design by Controlling Lean and Sweep Using an Innovative Iterative Inverse Design Method

2006 ◽  
Author(s):  
Jose´ C. Pa´scoa ◽  
Anto´nio C. Mendes
Keyword(s):  
Gas Turbines ◽  
Inverse Method ◽  
Design Method ◽  
Three Dimensions ◽  
Weak Part ◽  
Blade Thickness ◽  
Long Time ◽  
Time Marching ◽  
Time Lagged ◽  
Inverse Design Method

Inverse methods able to work in the transonic regime have for a long time been the weak part in the inverse method universe, albeit most of current gas turbines work in this regime. The present iterative inverse method is based on a Finite Volume time-marching scheme that is able to accurately compute the flowfield inside turbomachinery passages. In our design method we prescribe the acrodynamic load and blade thickness. Imposition of these variables precludes any existence and uniqueness problems and enables us to incorporate information regarding thermal and mechanical stresses in the first design stages. The method herein presented starts with an analysis of the flow in an initial geometry that is afterward adjusted by a modification in camber line. A new time-lagged formulation for the camber line generator will be presented. In order to design in three-dimensions a flexible stacking line generator will be introduced, as a mean to independently control sweep and lean for the blades. The results presented illustrate how an annular turbine cascade can be re-designed, with the present method, for better blade performance.

scholarly journals Controlling three-dimensional optical fields via inverse Mie scattering

2019 ◽  
Vol 5 (10) ◽  
pp. eaax4769 ◽  
Author(s):  
Alan Zhan ◽  
Ricky Gibson ◽  
James Whitehead ◽  
Evan Smith ◽  
Joshua R. Hendrickson ◽  
...  
Keyword(s):  
Design Method ◽  
Scattering Problem ◽  
Three Dimensional ◽  
Mie Scattering ◽  
Three Dimensions ◽  
Inverse Design ◽  
Optical Fields ◽  
Optical Elements ◽  
Space Optics ◽  
Inverse Design Method

Controlling the propagation of optical fields in three dimensions using arrays of discrete dielectric scatterers is an active area of research. These arrays can create optical elements with functionalities unrealizable in conventional optics. Here, we present an inverse design method based on the inverse Mie scattering problem for producing three-dimensional optical field patterns. Using this method, we demonstrate a device that focuses 1.55-μm light into a depth-variant discrete helical pattern. The reported device is fabricated using two-photon lithography and has a footprint of 144 μm by 144 μm, the largest of any inverse-designed photonic structure to date. This inverse design method constitutes an important step toward designer free-space optics, where unique optical elements are produced for user-specified functionalities.

Dual Point Redesign of Axial Turbines Using a Viscous Inverse Design Method

2009 ◽  
Author(s):  
Benedikt Roidl ◽  
Wahid Ghaly
Keyword(s):  
Inverse Method ◽  
Stokes Equations ◽  
Design Method ◽  
Single Point ◽  
Accurate Solution ◽  
Inverse Design ◽  
Suction Surface ◽  
Pressure Distributions ◽  
Wide Range ◽  
Inverse Design Method

A new dual-point inverse blade design method was developed and applied to the redesign of a highly loaded transonic vane, the VKI-LS89, and the first 2.5 stages of a low speed subsonic turbine, the E/TU-4 4-stage turbine that is built and tested at the university of Hannover, Germany. In this inverse method, 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 at both operating points. 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 dual-point inverse design method is then used to explore the effect of different choices of the pressure distributions on the suction surface of one or more rotor/stator on the blade/stage performance. The results show that single point inverse design resulted in a local performance improvement whereas the dual point design method allowed for improving the performance of both VKI-LS89 vane and E/TU-4 2.5 stage turbines over a wide range of operation.

Design Method for Turbomachine Blades With Finite Thickness by the Circulation Method

1997 ◽  
Vol 119 (3) ◽  
pp. 539-543 ◽  
Author(s):  
J. Jiang ◽  
T. Dang
Keyword(s):  
Inverse Method ◽  
Design Method ◽  
Guide Vane ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Inlet Guide Vane ◽  
Impulse Turbine ◽  
Blade Thickness ◽  
Flow Limit ◽  
Design Calculations

This paper presents a procedure to extend a recently developed three-dimensional inverse method for infinitely thin blades to handle blades with finite thickness. In this inverse method, the prescribed quantities are the blade pressure loading and the blade thickness distributions, and the calculated quantity is the blade mean camber line. The method is formulated in the fully inverse mode whereby the blade shape is determined iteratively using the flow-tangency condition along the blade surfaces. Design calculations are presented for an inlet guide vane, an impulse turbine blade, and a compressor blade in the two-dimensional inviscid- and incompressible-flow limit. Consistency checks are carried out for these design calculations using a panel analysis method and the analytical solution for the Gostelow profile.

scholarly journals Design Method for Turbomachine Blades With Finite Thickness by the Circulation Method

1994 ◽  
Author(s):  
Jun Jiang ◽  
Thong Dang
Keyword(s):  
Inverse Method ◽  
Incompressible Flows ◽  
Design Method ◽  
Guide Vane ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Inlet Guide Vane ◽  
Impulse Turbine ◽  
Blade Thickness ◽  
Design Calculations

This paper presents a procedure to extend a well-developed fully three-dimensional inverse method for infinitely-thin blades to handle blades with finite thickness. In this inverse method, the prescribed quantities are the blade pressure loading and the blade thickness distributions, and the calculated quantity is the blade geometry. The method is formulated in the fully inverse mode whereby the blade shape is determined iteratively using the flow-tangency condition along the blade surfaces. This technique is demonstrated here in the first instance for the design of cascaded blades in inviscid and incompressible flows. Design calculations are presented for an inlet guide vane, an impulse turbine blade, and a compressor blade. Consistency checks are carried out for these design calculations using a panel analysis method and the analytical solution for the Gostelow profile.

Design of the Blade Geometry of Swept Transonic Fans by 3D Inverse Design

2003 ◽  
Author(s):  
H. Watanabe ◽  
M. Zangeneh
Keyword(s):  
Inverse Method ◽  
Design Method ◽  
Pressure Ratio ◽  
Inverse Design ◽  
Specific Work ◽  
Design Practice ◽  
Blade Loading ◽  
Inverse Design Method ◽  
Transonic Fan ◽  
Blade Geometry

The application of sweep in the design of transonic fans has been shown to be an effective method of controlling the strength and position of the shock wave at the tip of transonic fan rotors, and the control of corner separations in stators. In rotors sweep can extend the range significantly. However, using sweep in conventional design practice can also result in a change in specific work and therefore pressure ratio. As a result, laborious iterations are required in order to recover the correct specific work and pressure ratio. In this paper, the blade geometry of a transonic fan is designed with sweep using a 3D inverse design method in which the blade geometry is computed for a specified distribution of blade loading. By comparing the resulting flow field in the conventionally and inversely designed swept rotors, it is shown that it is possible to apply sweep without the need to iterate to maintain pressure ratio and specific work when using the inverse method.

Redesigning Annular Turbine Blade Rows Using a Viscous-Inviscid Inverse Design Method

2008 ◽  
Author(s):  
J. C. Pa´scoa ◽  
A. C. Mendes ◽  
L. M. C. Gato
Keyword(s):  
Turbine Blade ◽  
Design Method ◽  
Thickness Distribution ◽  
Tangential Velocity ◽  
Inverse Design ◽  
Angle Distribution ◽  
Flow Angle ◽  
Design Algorithm ◽  
Blade Thickness ◽  
Inverse Design Method

This paper presents the results of the aerodynamic redesign of an annular turbine blade row. The inverse method herein applied is an extension to 3D of an iterative inverse design method based on the imposition of the blade load, thickness distribution and stacking line. We define a mass-averaged mean tangential velocity over one blade pitch, ru¯θ, as the main design variable, since its derivative is related to the aerodynamic load. A time-lagged formulation for the 3D camber surface generator is given in order to include the blade thickness distribution into the design algorithm. The hybrid viscous-inviscid design code comprises three main components: the blade update algorithm; a fast inviscid 3D Euler code; and a viscous analysis code. The blade geometry and flow conditions are typical of LP turbine nozzle guide vanes. The design method will demonstrate its ability to redesign blade rows that achieve lower flow losses and a more uniform exit flow angle distribution. The performance of the new blades is checked by means of a Navier-Stokes computation using the κ–ε turbulence model. The presented results show a minor decrease in the losses and a better redistribution of the exit flow angle.

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.

Redesign of a Highly Loaded Transonic Turbine Nozzle Blade Using a New Viscous Inverse Design Method

2007 ◽  
Author(s):  
Kasra Daneshkhah ◽  
Wahid Ghaly
Keyword(s):  
Inverse Method ◽  
Design Method ◽  
Guide Vane ◽  
Accurate Solution ◽  
Inverse Design ◽  
Arbitrary Lagrangian Eulerian ◽  
Pressure Distributions ◽  
Transonic Turbine ◽  
Inverse Design Method ◽  
Highly Loaded

The redesign of VKI-LS89 turbine vane, which is typical of a highly loaded transonic turbine guide vane is presented. The redesign is accomplished using a new inverse 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 (RANS) equations that are expressed in an arbitrary Lagrangian-Eulerian (ALE) form to account for mesh movement. A cell-vertex finite volume method is used to discretize the equations in space; time accurate integration is obtained using dual time stepping. An algebraic Baldwin-Lomax model is used for turbulence closure. The flow analysis formulation is first assessed against the LS89 experimental data. The inverse formulation that is implemented in the same code, is also assessed for its robustness and accuracy, by inverse designing the LS89 original geometry through running the inverse method with the original LS89 pressure distributions as target distributions but starting from an arbitrary geometry. The inverse design method is then used to redesign the LS89 using an arbitrary pressure distributions at a subsonic and a transonic outflow condition and the results are interpreted in terms of the blade overall aerodynamic performance.

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.

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.

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