Finite Element Computations of Transonic Viscous Flows with the Streamline Upwind Petrov-Galerkin (SUPG) Formulation

Finite Element Computations of Transonic Viscous Flows with the Streamline Upwind Petrov-Galerkin (SUPG) Formulation PDF Author: Constantin Bucur
Publisher:
ISBN:
Category :
Languages : en
Pages : 224

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Book Description
"Computations of transonic viscous flows are very challenging. The major difficulty comes from the discontinuity in the solution across a shock wave, causing undesired oscillations in the solution. In this work we focus on minimizing the oscillations by the use of a limiter to control the amount of diffusivity. This limiter provides the right amount of viscosity to capture a sharp shock and an accurate solution in high gradient regions. The limiter employs changes in pressure and entropy and has been implemented into the Streamline Upwind Finite Element Method. A mesh adaptation strategy has been employed to further enhance the accuracy of the solution. Results of simulations over RAE 2822 airfoil and ONERA M6 wing indicate significant improvements to the solution with this implementation." --

Finite Element Computations of Transonic Viscous Flows with the Streamline Upwind Petrov-Galerkin (SUPG) Formulation

Finite Element Computations of Transonic Viscous Flows with the Streamline Upwind Petrov-Galerkin (SUPG) Formulation PDF Author: Constantin Bucur
Publisher:
ISBN:
Category :
Languages : en
Pages : 224

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Book Description
"Computations of transonic viscous flows are very challenging. The major difficulty comes from the discontinuity in the solution across a shock wave, causing undesired oscillations in the solution. In this work we focus on minimizing the oscillations by the use of a limiter to control the amount of diffusivity. This limiter provides the right amount of viscosity to capture a sharp shock and an accurate solution in high gradient regions. The limiter employs changes in pressure and entropy and has been implemented into the Streamline Upwind Finite Element Method. A mesh adaptation strategy has been employed to further enhance the accuracy of the solution. Results of simulations over RAE 2822 airfoil and ONERA M6 wing indicate significant improvements to the solution with this implementation." --

Numerical Computation of Transonic Flows by Finite-element and Finite-difference Methods

Numerical Computation of Transonic Flows by Finite-element and Finite-difference Methods PDF Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information Office
Publisher:
ISBN:
Category : Aerodynamics, Transonic
Languages : en
Pages : 132

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Numerical Computation of Transonic Flows by Finite-element and Finite-diffence Methods

Numerical Computation of Transonic Flows by Finite-element and Finite-diffence Methods PDF Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information Office
Publisher:
ISBN:
Category : Aerodynamics, Transonic
Languages : en
Pages : 142

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Book Description


Computational Methods for Turbulent, Transonic, and Viscous Flows

Computational Methods for Turbulent, Transonic, and Viscous Flows PDF Author: Jean-André Essers
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 376

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Petrov-Galerkin Finite Element Formulations for Incompressible Viscous Flows

Petrov-Galerkin Finite Element Formulations for Incompressible Viscous Flows PDF Author: Paulo Angusto Berquo de Sampaio
Publisher:
ISBN:
Category : Finite element method
Languages : en
Pages :

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Introduction to the Numerical Analysis of Incompressible Viscous Flows

Introduction to the Numerical Analysis of Incompressible Viscous Flows PDF Author: William Layton
Publisher: SIAM
ISBN: 0898718902
Category : Mathematics
Languages : en
Pages : 220

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Book Description
Introduction to the Numerical Analysis of Incompressible Viscous Flows treats the numerical analysis of finite element computational fluid dynamics. Assuming minimal background, the text covers finite element methods; the derivation, behavior, analysis, and numerical analysis of Navier-Stokes equations; and turbulence and turbulence models used in simulations. Each chapter on theory is followed by a numerical analysis chapter that expands on the theory. This book provides the foundation for understanding the interconnection of the physics, mathematics, and numerics of the incompressible case, which is essential for progressing to the more complex flows not addressed in this book (e.g., viscoelasticity, plasmas, compressible flows, coating flows, flows of mixtures of fluids, and bubbly flows). With mathematical rigor and physical clarity, the book progresses from the mathematical preliminaries of energy and stress to finite element computational fluid dynamics in a format manageable in one semester. Audience: this unified treatment of fluid mechanics, analysis, and numerical analysis is intended for graduate students in mathematics, engineering, physics, and the sciences who are interested in understanding the foundations of methods commonly used for flow simulations.

Advances in Computational Fluid-Structure Interaction and Flow Simulation

Advances in Computational Fluid-Structure Interaction and Flow Simulation PDF Author: Yuri Bazilevs
Publisher: Birkhäuser
ISBN: 3319408275
Category : Mathematics
Languages : en
Pages : 487

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Book Description
This contributed volume celebrates the work of Tayfun E. Tezduyar on the occasion of his 60th birthday. The articles it contains were born out of the Advances in Computational Fluid-Structure Interaction and Flow Simulation (AFSI 2014) conference, also dedicated to Prof. Tezduyar and held at Waseda University in Tokyo, Japan on March 19-21, 2014. The contributing authors represent a group of international experts in the field who discuss recent trends and new directions in computational fluid dynamics (CFD) and fluid-structure interaction (FSI). Organized into seven distinct parts arranged by thematic topics, the papers included cover basic methods and applications of CFD, flows with moving boundaries and interfaces, phase-field modeling, computer science and high-performance computing (HPC) aspects of flow simulation, mathematical methods, biomedical applications, and FSI. Researchers, practitioners, and advanced graduate students working on CFD, FSI, and related topics will find this collection to be a definitive and valuable resource.

Numerical Methods for the Computation of Inviscid Transonic Flows with Shock Waves

Numerical Methods for the Computation of Inviscid Transonic Flows with Shock Waves PDF Author: Arthur Rizzi
Publisher: Springer-Verlag
ISBN: 3663140083
Category : Science
Languages : de
Pages : 283

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Book Description


A Contribution to the Finite Element Analysis of High-Speed Compressible Flows and Aerodynamics Shape Optimization

A Contribution to the Finite Element Analysis of High-Speed Compressible Flows and Aerodynamics Shape Optimization PDF Author: Mohammad Kouhi
Publisher:
ISBN:
Category :
Languages : en
Pages : 111

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Book Description
This work covers a contribution to two most interesting research elds in aerodynamics, the fi nite element analysis of high-speed compressible flows (Part I) and aerodynamic shape optimization (Part II). The fi rst part of this study aims at the development of a new stabilization formulation based on the Finite Increment Calculus (FIC) scheme for the Euler and Navier-Stokes equations in the context of the Galerkin nite element method (FEM). The FIC method is based on expressing the balance of fluxes in a spacetime domain of nite size. It is tried to prevent the creation of instabilities normally presented in the numerical solutions due to the high convective term and sharp gradients. In order to overcome the typical instabilities happening in the numerical solution of the high-speed compressible flows, two stabilization terms, called streamline term and transverse term, are added through the FIC formulation in space-time domain to the original conservative equations of mass, momentum and energy. Generally, the streamline term holding the direction of the velocity is responsible for stabilizing the spurious solutions produced from the convective term while the transverse term smooths the solution in the high gradient zones. An explicit fourth order Runge-Kutta scheme is implemented to advance the solution in time. In order to investigate the capability of the proposed formulation, some numerical test examples corresponding to subsonic, transonic and supersonic regimes for inviscid and viscous flows are presented. The behavior of the proposed stabilization technique in providing appropriate solutions has been studied especially near the zones where the solution has some complexities such as shock waves, boundary layer, stagnation point, etc. Although the derived methodology delivers precise results with a nearly coarse mesh, the mesh refinement technique is coupled in the solution to create a suitable mesh particularly in the high gradient zones. The comparison of the numerical results obtained from the FIC formulation with the reference ones demonstrates the robustness of the proposed method for stabilization of the Euler and Navier-Stokes equations. It is observed that the usual oscillations occur in the Galerkin FEM, especially near the high gradient zones, are cured by implementing the proposed stabilization terms. Furthermore, allowing the adaptation framework to modify the mesh, the quality of the results improves signi cantly. The second part of this thesis proposes a procedure for aerodynamic shape optimization combining Genetic Algorithm (GA) and mesh re nement technique. In particular, it is investigated the e ect of mesh re nement on the computational cost and solution accuracy during the process of aerodynamic shape optimization. Therefore, an adaptive remeshing technique is joined to the CFD solver for the analysis of each design candidate to guarantee the production of more realistic solutions during the optimum design process in the presence of shock waves. In this study, some practical transonic airfoil design problems using adap- tive mesh techniques coupled to Multi-Objective Genetic Algorithms (MOGAs) and Euler flow analyzer are addressed. The methodology is implemented to solve three practical design problems; the fi rst test case considers a reconstruction design optimization that minimizes the pressure error between a prede ned pressure curve and candidate pressure distribution. The second test considers the total drag minimization by designing airfoil shape operating at transonic speeds. For the final test case, a multi-objective design optimization is conducted to maximize both the lift to drag ratio (L/D) and lift coe cient (Cl). The solutions obtained with and without adaptive mesh re nement are compared in terms of solution accuracy and computational cost. These design problems under transonic speeds need to be solved with a ne mesh, particularly near the object, to capture the shock waves that will cost high computational time and require solution accuracy. By comparison of the the numerical results obtained with both optimization problems, the obtainment of direct bene ts in the reduction of the total computational cost through a better convergence to the final solution is evaluated. Indeed, the improvement of the solution quality when an adaptive remeshing technique is coupled with the optimum design strategy can be judged.

Finite Element Methods for Viscous Incompressible Flows

Finite Element Methods for Viscous Incompressible Flows PDF Author: Max D. Gunzburger
Publisher: Elsevier
ISBN: 0323139825
Category : Technology & Engineering
Languages : en
Pages : 292

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Book Description
Finite Element Methods for Viscous Incompressible Flows examines mathematical aspects of finite element methods for the approximate solution of incompressible flow problems. The principal goal is to present some of the important mathematical results that are relevant to practical computations. In so doing, useful algorithms are also discussed. Although rigorous results are stated, no detailed proofs are supplied; rather, the intention is to present these results so that they can serve as a guide for the selection and, in certain respects, the implementation of algorithms.