Sökning: "ship resistance calculation"

Hittade 3 avhandlingar innehållade orden ship resistance calculation.

  1. 1. The Enemy Below - Adhesion and Friction of Ship Hull Fouling

    Författare :Dinis Oliveira; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ship resistance; in-water hull cleaning; roughness; biofouling; hull grooming; frictional resistance; adhesion strength; turbulent boundary layer; hull form factor;

    Sammanfattning : Below the waterline, commercial ships are good targets for marine organisms to attach and proliferate, a problem commonly known as biofouling. A fouled hull means higher hydrodynamic resistance, which can result in significant fuel penalties. LÄS MER

  3. 2. On Turbulence Modelling for Bilge Vortices: A Test of Eight Models for Three Cases

    Författare :Urban Svennberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wake; turbulence modelling; nonlinear eddy-viscosity model; bilge vortices; ship flow; jet; Navier-Stokes equation; two-equation model; Reynolds stress model; vortex;

    Sammanfattning : This work is a test, in three steps, of turbulence models for the calculation of the flow field around ships. Eight models ranging from k-e and k-w models to a Reynolds-stress model (RSM) are tested. LÄS MER

  4. 3. Potential Flow Panel Methods for the Calculation of Free-surface Flows with Lift

    Författare :Carl-Erik Janson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; desingularized; shape optimization; Rankine source; waves; OCTOPUS; dipole; MMA; Dawson operator; boundary layer; vortex; Method of Moving Asymptotes; nonlinear; sailing yacht; four point operator; surface piercing wing; Navier-Stokes; numerical method; lift force; raised panel method; discrete Fourier transform; collocation point shift; potential flow; CFD; free surface; induced drag; SHIPFLOW; dispersion; damping; analytical method; hydrofoil;

    Sammanfattning : Two non-linear Rankine-source panel methods are developed and implemented in the same computer code. The first method uses a four-point upwind operator on the free-surface to compute the velocity derivatives and to enforce the radiation condition while the second method uses an analytical expression for the velocity derivatives and a collocation point shift one panel upstream to prevent upstream waves. LÄS MER