Numerical simulation of airfoil vibrations induced by turbulent flow

AbstractThe subject of this paper is the numerical simulation of the interaction between two-dimensional incompressible viscous flow and a vibrating airfoil. A solid elastically supported airfoil with two degrees of freedom, which can rotate around the elastic axis and oscillate in the vertical direction, is considered. The numerical simulation consists of the stabilized finite element solution of the Reynolds averaged Navier–Stokes equations with algebraic models of turbulence, coupled with the system of ordinary differential equations describing the airfoil motion. Since the computational domain is time dependent and the grid is moving, the Arbitrary Lagrangian–Eulerian (ALE) method is used. The developed method was applied to the simulation of flow-induced airfoil vibrations

Numerical simulation of interaction of fluids and solid bodies

The subject of this thesis is modelling and numerical simulation of the interaction of two-dimensional incompressible viscous flow and a vibrating airfoil. A solid airfoil with two degrees of freedom, which can rotate around the elastic axis and oscillate in the vertical direction, is considered. The numerical simulation consists of the finite element solution of the Navier-Stokes equations coupled with the system of ordinary differential equations describing the airfoil motion. The time dependent computational domain and a moving grid are taken into account with the aid of the Arbitrary Lagrangian-Eulerian (ALE) formulation of the Navier-Stokes equations. High Reynolds numbers up to 106 require the application of a suitable stabilization of the finite element discretization and application of a turbulent model. We apply the algebraic turbulent models, which were designed by Baldwin and Lomax and by Rostand. As a result a sufficiently accurate and robust method is developed, which was tested by the simulation of flow along a flat plate and applied to the computation of pressure distribution along the airfoil with forced vibrations

HP-FEM for Coupled Problems in Fluid Dynamics

of dissertation hp-FEM FOR COUPLED PROBLEMS IN FLUID DYNAMICS Lenka Dubcová The thesis is concerned with the solution of multiphysics problems de- scribed by partial differential equations using higher-order finite element method (hp-FEM). Basics of hp-FEM are described, together with some practical details and challenges. The hp-adaptive strategy, based on the reference solution and meshes with arbitrary level hanging nodes, is dis- cussed. The thesis is mainly concerned with the extension of this strategy to monolithical solution of coupled multiphysics problems, where each physical field exhibits different qualitative behavior. In such problems, each physical field is discretized on an individual mesh automatically obtained by the adaptive algorithm to suit the best the corresponding so- lution component. Moreover, the meshes can change in time, following the needs of the solution components. All described methods and tech- nologies are demonstrated on several examples throughout the thesis, where comparisons with traditionally used approaches are shown

Numerická simulace interakce tekutin a tuhých těles

of dissertation hp-FEM FOR COUPLED PROBLEMS IN FLUID DYNAMICS Lenka Dubcová The thesis is concerned with the solution of multiphysics problems de- scribed by partial differential equations using higher-order finite element method (hp-FEM). Basics of hp-FEM are described, together with some practical details and challenges. The hp-adaptive strategy, based on the reference solution and meshes with arbitrary level hanging nodes, is dis- cussed. The thesis is mainly concerned with the extension of this strategy to monolithical solution of coupled multiphysics problems, where each physical field exhibits different qualitative behavior. In such problems, each physical field is discretized on an individual mesh automatically obtained by the adaptive algorithm to suit the best the corresponding so- lution component. Moreover, the meshes can change in time, following the needs of the solution components. All described methods and tech- nologies are demonstrated on several examples throughout the thesis, where comparisons with traditionally used approaches are shown.disertační práce hp-FEM PRO SDRUŽENÉ PROBLÉMY V MECHANICE TEKUTIN Lenka Dubcová Disertační práce se zabývá řešením multifyzikálních problemů pop- saných parciálními diferenciálními rovnicemi metodou konečných prvků vyšších řádů (hp-FEM). Základy této metody jsou popsány společně s praktickými detaily a problémy. Dále je popsána nová hp-adaptivní strate- gie založená na tzv. referenčním řešení a sítích s libovolným stupněm visících uzlů. Práce se především zabývá rozšířením této metody pro monolitické řešení multifyzikálních problémů, kde každá fyzikální složka vykazuje jiné kvalitativní chování a je tedy diskretizována na vlastní adap- tivně získané síti vyhovující chování příslušné složky řešení. Tyto sítě se navíc mohou měnit v čase podle potřeb jednotlivých složek řešení. Všechny popsané metody jsou v práci demonstrovány na několika přík- ladech společně se srovnáním s tradičně používanými metodami.Department of Numerical MathematicsKatedra numerické matematikyFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

HP-FEM pro sdužené peoblémy v mechanice tekutin

The thesis is concerned with the solution of multiphysics problems described by partial differential equations using higher-order finite element method (hp-FEM). Basics of hp-FEM are described, together with some practical details and challenges. The hp-adaptive strategy, based on the reference solution and meshes with arbitrary level hanging nodes, is discussed. The thesis is mainly concerned with the extension of this strategy to monolithical solution of coupled multiphysics problems, where each physical field exhibits different qualitative behavior. In such problems, each physical field is discretized on an individual mesh automatically obtained by the adaptive algorithm to suit the best the corresponding solution component. Moreover, the meshes can change in time, following the needs of the solution components. All described methods and technologies are demonstrated on several examples throughout the thesis, where comparisons with traditionally used approaches are shown.Disertační práce se zabývá řešením multifyzikálních problémů popsaných parciálními diferenciálními rovnicemi metodou konečných prvků vyšších řádů (hp-FEM). Základy této metody jsou popsány společně s praktickými detaily a problémy. Dále je popsána nová hp-adaptivní strategie založená na tzv. referenčním řešení a stítích s libovolným stupněm visících uzlů. Práce se především zabývá rozšířením této metody pro monolitické řešení multifyzikálních problémů, kde každá fyzikální složka vykazuje jiné kvalitativní chování a je tedy diskretizována na vlastní adaptivně získané síti vyhovující chování přístušné složky řešení. Tyto sítě se navíc mohou měnit v čase podle potřeb jednotlivých složek řešení. Všechny popsané metody jsou v práci demonstrovány na několika příkladech společně se srovnáním s tradičně používanými metodami.Katedra numerické matematikyDepartment of Numerical MathematicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult