Sökning: "Vorticity"

Visar resultat 11 - 15 av 33 uppsatser innehållade ordet Vorticity.

  1. 11. Dissipative Perturbations on LRS Class II Cosmologies Using the 1+1+2 Covariant Split of Spacetime

    Master-uppsats, Umeå universitet/Institutionen för fysik

    Författare :Philip Semrén; [2020]
    Nyckelord :;

    Sammanfattning : By including dissipative fluxes in the description, this thesis extends previous results regarding first order perturbations on homogeneous and hypersurface orthogonal locally rotationally symmetric (LRS) class II cosmologies using the 1 + 1 + 2 covariant split of spacetime. Whereas previous works consider perturbations of perfect fluid type, perturbations pertaining to heat flux and fluid viscosity are here studied with the aim to ascertain their effect on the evolution of the fluid vorticity. LÄS MER

  3. 12. Steady ideal flows with vorticity in toroidal domains and periodic cylinders

    Master-uppsats, Lunds universitet/Matematik LTH; Lunds universitet/Matematik (naturvetenskapliga fakulteten)

    Författare :Gustav Jillbratt; [2020]
    Nyckelord :Partial differential equations; Euler equation; Vorticity; Fluid dynamics; Mathematics and Statistics;

    Sammanfattning : In a paper from 1970, Lortz constructs rotational solutions to the steady Euler equation in toroidal domains using a fixed point method. We shall review this method and rewrite it using Banach's fixed point theorem. LÄS MER

  4. 13. A simplified vortex method for wind turbine simulation

    Master-uppsats, KTH/Strömningsmekanik och Teknisk Akustik

    Författare :Sandro Malusa; [2019]
    Nyckelord :Wind turbine; Vortex model; Numerical wake model; Vortex sheet; Vortex filament; Tjaereborg; Biot-Savart law; Iterative method;

    Sammanfattning : A new vortex model for wind turbines was developed in order to evaluate the loads at the blades and other important characteristics of interest for the wind industry such as power and thrust coefficients. Nowadays, the calculation of these quantaties is done in a reliable and precise manner with LES simulation using actuator line or actuator disk models. LÄS MER

  5. 14. Influence on tip leakage flow in a compressor cascade with plasma actuation

    Master-uppsats, KTH/Skolan för industriell teknik och management (ITM)

    Författare :Haotian Wang; [2019]
    Nyckelord :Flow control; DBD Plasma actuation; phenomenological model; numerical simulation; tip leakage flow; compressor cascade.; Flödesreglering; DBD Plasma‐aktuator; numerisk simulering; toppspelsflöde; kompressor kaskad.;

    Sammanfattning : As one of the key components of aero engines, compressor is required to endure higher pressure,  possess  higher  efficiency  and  wider  operating  range. Intensive studies have been made on tip leakage flow and researchers find that by reasonably organizing tip leakage flow, aero engines are  more likely to achieve better performance and reliability. LÄS MER

  7. 15. Large Eddy Simulation of Turbulent Flow over a Backward-Facing Step

    Master-uppsats, Uppsala universitet/Institutionen för informationsteknologi

    Författare :Edmond Shehadi; [2018]
    Nyckelord :;

    Sammanfattning : This work studies the effect of grid resolution and subgrid scale modeling on the predictive accuracy of Large Eddy Simulation. In particular, the problems considered are: turbulent flow over a backward-facing step and fully-developed turbulent channel flow. LÄS MER