Sökning: "adjoint solutions"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden adjoint solutions.

  1. 1. Adjoint-based aerodynamic shape optimization

    Författare :Olivier Amoignon; Martin Berggren; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

    Sammanfattning : An adjoint system of the Euler equations of gas dynamics is derived in order to solve aerodynamic shape optimization problems with gradient-based methods. The derivation is based on the fully discrete flow model and involves differentiation and transposition of the system of equations obtained by an unstructured and node-centered finite-volume discretization. LÄS MER

  3. 2. Receptivity of crossflow-dominated boundary layers

    Författare :David Tempelmann; Ardeshir Hanifi; Dan Henningson; Anatoli Tumin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Receptivity; three-dimensional boundary layers; optimal growth; adjoint solutions; swept wing;

    Sammanfattning : This thesis deals with receptivity mechanisms of three-dimensional, crossflow-dominated boundary layers. The receptivity of two model problems, a swept-flat-plate and a swept-wing boundary layer, is investigated by solving the parabolised stability equations (PSE) as well as by performing direct numerical simulations (DNS). LÄS MER

  4. 3. On adjoint symmetries and reciprocal Bäcklund transformations of evolution equations

    Författare :Staffan Lundberg; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Sammanfattning : The aim of this Licentiate Thesis is to discuss special transformations and so-called adjoint symmetries of nonlinear partial differential equations. Nonlinear partial differential equations play an important role in the description of many physical phenomena. LÄS MER

  5. 4. Topology optimization of antennas and waveguide transitions

    Författare :Emadeldeen Hassan; Martin Berggren; Daniel Noreland; Eddie Wadbro; Mats Gustafsson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; topology optimization; antennas; waveguide transition; finite-difference time-domain; gradient-based optimization; adjoint-field problem; microwave devices.; business data processing; administrativ databehandling;

    Sammanfattning : This thesis introduces a topology optimization approach to design, from scratch, efficient microwave devices, such as antennas and waveguide transitions. The design of these devices is formulated as a general optimization problem that aims to build the whole layout of the device in order to extremize a chosen objective function. LÄS MER

  7. 5. Neutronics in reactors with propagating perturbations

    Författare :Anders Jonsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; one-group theory; Green s function; Molten Salt Reactors; two-group theory; neutron noise; propagating perturbations;

    Sammanfattning : This thesis contains several studies of the properties of neutron noise, primarily in Molten Salt Reactors and other reactors with propagating perturbations. Both one- and two-group diffusion theory are employed to investigate the differences that arise from the movement of the fuel. LÄS MER