Direct Design of Airfoil Shape With a Prescribed Surface Pressure

Ashrafizadeh, Ali; Raithby, G. D.; Stubley, G. D.

doi:10.1080/104077990502989

Cited by 24 publications

(24 citation statements)

References 16 publications

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“…It is expected that the methodology suggested in [3] can be employed to solve the Euler flow airfoil design problems as well.…”

Section: Resultsmentioning

confidence: 99%

“…This article presents a direct (fully coupled) SSD method based on the ideas proposed by Ashrafizadeh et al which has only been applied in the context of linear ideal fluid flows before [1][2][3]. The nonlinear set of Euler equations are used here as the flow governing equations and a number of shape design problems are solved to validate the method and to provide shape design examples in subsonic and supersonic internal flows.…”

Section: Introductionmentioning

confidence: 98%

“…A novel direct shape design method was proposed by Ashrafizadeh et al [1][2][3]. They basically showed that a fully coupled formulation of the SSD problem could be solved in the physical domain using a simple extension of commonly used CFD algorithms.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A direct design approach using the Euler equations

Taiebi-Rahni

Ghadak

Ashrafizadeh

2008

Inverse Problems in Science and Engineering

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Recently, a fully coupled formulation of the surface shape design problem, called the direct design approach, has been proposed in which both the target surface pressure and the unknown nodal coordinates appear explicitly in the formulations. The proposed method is generally applicable, but in the past it has only been applied in the context of ideal fluid flows [Ashrafizadeh, A., , 505-527]. The present article extends the application of this method to the design of ducts carrying flows governed by the nonlinear coupled Euler equations, using a cell-centered finite volume method to discretize the governing equations. The details of the linearization and the imposition of the target pressure are discussed in this article. Also, the validation test cases and the design examples are presented, which show the robustness of the method in handling complex geometries and complex physical phenomena (such as shock waves). It is also shown that the computational cost of a direct shape design solution is comparable to the solution of the corresponding analysis problem.

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“…It is expected that the methodology suggested in [3] can be employed to solve the Euler flow airfoil design problems as well.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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A direct design approach using the Euler equations

Taiebi-Rahni

Ghadak

Ashrafizadeh

2008

Inverse Problems in Science and Engineering

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“…Shape design involving fluid flow means determining a flow geometry that will satisfy the governing flow equations and boundary conditions while simultaneously meeting one or more design criteria, such as achieving the desired shape of an aerofoil, flow split in a T-junction or pressure loss in a return bend (Ashrafizadeh, Raithby, and Stubley 2004;Dulikravich 1992;Verstraete et al 2013). When the specified target is achieved by seeking an appropriate shape of the flow domain, the problem is known as inverse shape design.…”

Section: Introductionmentioning

confidence: 99%

Shape optimization of flow split ducting elements using an improved Box complex method

Srinivasan

Balamurugan

Jayanti

2016

Engineering Optimization

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Iterative search methods, such as the Box complex method, can be used for inverse shape design problems. In the present article, an improved version of the Box complex method is proposed specifically for computational fluid dynamics-based optimization of fluid flow ducting elements. The original Box complex method is improved by (1) assigning non-uniform weights for the estimation of the centroid, (2) using a reduced reflection factor for accelerated convergence, and (3) introducing measures to prevent premature breakdown of the iterative process. The success of the improved Box complex method over the original Box complex method is demonstrated on two benchmark functions and by applying it to two fluid flow problems of engineering. The improved method is shown to substantially accelerate the convergence with approximately 50% reduction in computational effort for the T-junction and manifold problems. ARTICLE HISTORYInverse shape design; internal flow; computational fluid dynamics; search algorithms; Box complex method; computational efficiency

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“…In an inverse shape design problem, the shape of part of the boundary of the domain is unknown and target values for some field variables are prescribed instead. For example, airfoils can be designed to achieve a prescribed surface pressure distribution in an aerodynamic inverse shape design problem [2,3] or ducts can be designed to prevent pressure over-shoot and under-shoot and to minimize the head loss due to the flow separation in viscous flows [4,5].…”

Section: Introductionmentioning

confidence: 99%

A semi-coupled solution algorithm in aerodynamic inverse shape design

Ashrafizadeh

Okhovat

Pourbagian

et al. 2011

Inverse Problems in Science and Engineering

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The numerical solution of an inverse airfoil design problem requires computational tools for grid generation, flow solution and the geometry update to provide the desirable shape corresponding to a given surface target pressure. Un-coupled as well as fully and semi-coupled shape design strategies have already been developed and employed. The target pressure is directly imposed in the fully coupled approach in contrast to un-coupled methods. Available semi-coupled methods use additional computational tools to couple the flow solver and the shape updater to directly impose the target pressure. In this article, a semicoupled numerical shape design strategy is introduced, in the context of an ideal flow model, in which the target tangential velocity is directly imposed while no additional computational tool is employed. Numerical test cases, implemented on both structured and unstructured grids, are carried out to compare the performance of the proposed method with an adjoint-based optimization technique. Results show that the semi-coupled method has a two to three times faster convergence rate as compared to the adjoint approach. However, the semicoupled solution convergence rate usually stalls after three orders of magnitude reduction of the objective function, while the un-coupled optimization method provides a more accurate solution. Therefore, a hybrid solution methodology is also advised, which provides faster convergence as well as lower computational errors as compared to both semi and un-coupled methods.

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Direct Design of Airfoil Shape With a Prescribed Surface Pressure

Cited by 24 publications

References 16 publications

A direct design approach using the Euler equations

A direct design approach using the Euler equations

Shape optimization of flow split ducting elements using an improved Box complex method

A semi-coupled solution algorithm in aerodynamic inverse shape design

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