Sökning: "Finite element methods"

Visar resultat 11 - 15 av 580 avhandlingar innehållade orden Finite element methods.

  1. 11. Adaptive Finite Element Methods for Optimal Control Problems

    Författare :Karin Kraft; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dual weighted residual; adaptive; Newton method; variational inequality; vehicle dynamics.; multilevel algorithm; discontinuous Galerkin method; a posteriori error estimate; finite element method; optimal control; control constraint;

    Sammanfattning : In this thesis we study the numerical solution of optimal control problems. The problems considered consist of a systemof differential equations, the state equations, which are governed bya control variable. The goal is to determine the states and controls which minimize a given cost functional. LÄS MER

  3. 12. Analysis of Adaptive Finite Element Methods

    Författare :Mats G Larson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis is concerned with the analysis and design of adaptive finite element methods for a variety of differential equations in mechanics and physics, including linear and semilinear elliptic equations, eigenvalue problems, the stationary Navier-Stokes equations, and Hamiltonian systems. The analysis focuses on sharp a posteriori error estimates, sharp a priori error estimates, stability properties, and the design of adaptive algorithms. LÄS MER

  4. 13. High Performance Adaptive Finite Element Methods : With Applications in Aerodynamics

    Författare :Niclas Jansson; Johan Hoffman; Johan Jansson; Vincent Heuveline; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The massive computational cost for resolving all scales in a turbulent flow makes a direct numerical simulation of the underlying Navier-Stokes equations impossible in most engineering applications. Recent advances in adaptive finite element methods offer a new powerful tool in Computational Fluid Dynamics (CFD). LÄS MER

  5. 14. Simulation of contact, friction and wear in gears : a finite element approach

    Författare :Olle Lundvall; Linköpings universitet; []
    Nyckelord :Gears; Gear noise; Contact mechanics; Simulation; Friction; Wear; Transmission error;

    Sammanfattning : In this thesis, resent methods in computational contact mechanics is brought into the process of gear design. The finite element method is used to model two elastic bodies in contact. By defining a contact interface between these two bodies, constitutive laws, regarding normal contact, friction and wear, are included. LÄS MER

  7. 15. Transport theory and finite element methods for mesoscopic superconducting devices

    Författare :Kevin Marc Seja; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; non-equilibrium superconductivity; finite element methods; unconventional superconductors; quasiclassical theory; transport theory;

    Sammanfattning : At low temperatures, electrons in a superconductor exhibit pairing correlations that result in a macroscopic, phase-coherent ground state. This leads to peculiar electromagnetic properties such as the flow of dissipationless charge currents and expelling of external magnetic fields. LÄS MER