Inverse Design of Transonic Wings Using Wing Planform and Target Pressure Optimization

2001 ◽  
Vol 38 (4) ◽  
pp. 644-652 ◽  
Author(s):  
Taisul Ahn ◽  
Hyoung-Jin Kim ◽  
Chongam Kim ◽  
Oh-Hyun Rho
Keyword(s):  
Inverse Design ◽  
Target Pressure

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.

Inverse Design of Airfoils Using Target Pressure Optimization

2013 ◽  
Vol 694-697 ◽  
pp. 3183-3188
Author(s):  
Ya Feng Liu ◽  
Dong Li Ma
Keyword(s):  
Genetic Algorithm ◽  
Laminar Flow ◽  
Design Method ◽  
Spline Interpolation ◽  
Inverse Design ◽  
Spline Functions ◽  
Control Points ◽  
B Spline ◽  
Pressure Distributions ◽  
Target Pressure

The Direct Iterative Surface Curvature (DISC) airfoil design method developed by NASA Langley, which is one of the inverse design methods, is robust and effective. In order to determine the target pressure distributions of airfoils, this paper used the uniformed B-spline interpolation for the parameterization of the target pressure, and a Genetic Algorithm (GA) was used to optimize the coordinates of the control points of the B-spline functions. Two cases were given to prove the effect of the DISC design method. A laminar flow airfoil was then designed using DISC after a target pressure had been determined by a GA. Results show that the DISC method based on target pressure optimization using GAs is pretty effective.

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.

Inverse Design of Airfoils Using Convolutional Neural Network and Deep Neural Network

2021 ◽  
Author(s):  
Amit Kumar ◽  
Nagabhushana Rao Vadlamani
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Convolutional Neural Network ◽  
Pressure Distribution ◽  
Mean Squared Error ◽  
Inverse Design ◽  
Batch Size ◽  
Squared Error ◽  
Order Of Magnitude ◽  
Target Pressure

Abstract In this paper, we compare the efficacy of two neural network based models: Convolutional Neural Network (CNN) and Deep Neural Networks (DNN) to inverse design the airfoil shapes. Given the pressure distribution over the airfoil in pictorial (for CNN) or numerical form (for DNN), the trained neural networks predict the airfoil shapes. During the training phase, the critical hyper-parameters of both the models, namely — learning rate, number of epochs and batch size, are tuned to reduce the mean squared error (MSE) and increase the prediction accuracy. The training parameters in DNN are an order of magnitude lower than that of CNN and hence the DNN model is found to be ≈ 7× faster than the CNN. In addition, the accuracy of DNN is also observed to be superior to that of CNN. After processing the raw airfoil shapes, the smoothed airfoils are shown to yield the target pressure distribution thereby validating the framework.

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.

Aerodynamic Inverse Blade Design of Axial Compressors in Three-Dimensional Flow Using a Commercial CFD Program

2017 ◽  
Author(s):  
Araz Arbabi ◽  
Wahid Ghaly ◽  
Adam Medd
Keyword(s):  
Viscous Flow ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Inverse Design ◽  
Axial Fan ◽  
Time Step ◽  
Transonic Compressor ◽  
Blade Thickness ◽  
Target Pressure ◽  
Virtual Velocity

An aerodynamic inverse design method is developed for the simulation of three-dimensional viscous flow over blades, it is implemented into a commercial CFD program, namely ANSYS-CFX, and it is applied to the design of a transonic compressor stage. The implementation is validated for Rotor 37; it is then assessed in the redesign of Stage 67 stator. One set of design choices is to prescribe a target blade pressure loading and blade thickness distributions and a stacking line from hub to tip. The blade walls are assumed to be moving with a virtual velocity that would asymptotically drive the blade to the shape that would correspond to the specified target pressure distribution. This virtual velocity distribution is computed from the difference between the computed and the target pressure distributions. This inverse design approach is fully consistent with the viscous flow assumption and is independent of the CFD approach taken. The Arbitrary Lagrangian-Eulerian formulation of the unsteady Reynolds-Averaged Navier Stokes equations is solved in a time accurate fashion with the blade motion being the source of unsteadiness. At each time step, the blade shape is modified and dynamic meshing is used to remesh the fluid flow domain. To demonstrate the ability of this approach, it is applied to redesign the stator of a transonic axial fan, Stage 67, to improve its performance.

Aerodynamic Design of S-Shaped Diffusers Using Ball Spine Inverse Design Method

2014 ◽  
Author(s):  
Ali Madadi ◽  
Mahdi Nili-Ahmadabadi ◽  
Mohammad Jafar Kermani
Keyword(s):  
Design Method ◽  
Inverse Design ◽  
Cross Sectional ◽  
Design Algorithm ◽  
Flow Solver ◽  
Pressure Distributions ◽  
Duct Geometry ◽  
Sst Turbulence Model ◽  
Target Pressure ◽  
Inverse Design Method

Recently, an inverse design algorithm called ball-spine algorithm (BSA) is introduced for the design of 2-D ducts. In this approach, the walls are considered as a set of virtual balls that can freely move along the straight directions called spines. In the present work the method is developed for quasi 3-D design of S-shaped ducts with a predefined width. To do so, the upper and lower lines of the S-duct symmetric section are modified under the BSA and then, the 3-D S-duct geometry is obtained based on elliptic cross sectional profiles. The target pressure distributions along the upper and lower lines are prescribed so that the separation does not occur. Finally, the flow through the designed S-duct is numerically analyzed using a viscous flow solver with the SST turbulence model to validate the designed S-duct performance.

scholarly journals DLR transonic inverse design code, extensions and modifications to increase versatility and robustness

2017 ◽  
Vol 121 (1245) ◽  
pp. 1733-1757 ◽  
Author(s):  
T. Streit ◽  
C. Hoffrogge
Keyword(s):  
Wind Tunnel ◽  
Original Method ◽  
Inverse Design ◽  
Test Cases ◽  
Swept Wing ◽  
Design Code ◽  
Tunnel Design ◽  
Wing Geometry ◽  
Target Pressure ◽  
Wind Tunnel Design

ABSTRACTThe DLR inverse design code computes the wing geometry for a prescribed target pressure distribution. It is based on the numerical solution of the integral inverse transonic small perturbation (TSP) equations. In this work, several extensions and modifications of the inverse design code are described. Results are validated with corresponding redesign test cases. The first modification concerns applications for high transonic Mach numbers or cases with strong shocks. The introduced modifications enable converged design solutions for cases where the original method failed. The second modification is the extension of the code to general non-planar wings. Previously, the design code was restricted to non-planar wing designs with small dihedral or to nacelle design. A third modification concerns aerofoil/wings designed for wind-tunnel design. In order to design a swept wing between two wind-tunnel walls, the solution method was extended to two symmetry planes. The introduced extensions and modifications have increased the robustness and range of applicability of the inverse design code.

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