Avancerad sökning

Visar resultat 6 - 10 av 310 avhandlingar som matchar ovanstående sökkriterier.

  1. 6. Numerical Simulation of High Reynolds Number Wall Bounded Flow

    Författare :Tobias Persson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; subgrid model; DES; high; validation; LES; numerical simulation; near-wall;

    Sammanfattning : In this thesis, four different numerical methods are used for predictions of high Reynoldsnumber (Re), wall bounded flows; Large Eddy Simulation (LES) with two different subgrid(turbulence) models, the One Equation Eddy Viscosity model (OEEVM) and the MixedModel (MM), Monotone Integrated LES (MILES), Detached Eddy Simulation (DES) andReynolds Averaged Navier Stokes (RANS). The LES calculations are combined with a wallmodel based on the law-of-the-wall and in DES a hybrid RANS/LES method is used forhandling the near wall region. LÄS MER

  3. 7. Robust Numerical Wall Functions Implemented in OpenFOAM

    Författare :Jon-Anders Bäckar; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; impinging jet; numerical wall function; Computational Fluid Dynamics; speed-up; OpenFOAM;

    Sammanfattning : This thesis presents two new numerical wall models for computing Reynolds-Averaged-Navier-Stokes (RANS) equations with low-Reynolds-number turbulence models. Theobjective is to considerably reduce the total central processing unit (CPU) cost of thenumerical simulations of wall bounded flows while maintaining the accuracy of anylow-Reynolds-number turbulence model. LÄS MER

  4. 8. EHL investigations using a hybrid technique : an experimental and numerical approach

    Författare :Alexei Jolkin; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

    Sammanfattning : This licentiate thesis deals with a hybrid experimental and numerical method, the so-called Hybrid Technique, to study film thickness and pressure distribution and to investigate the behaviour and properties of lubricants in highly loaded EHL conjunctions. The Hybrid Technique combines experimental studies and advanced numerical calculations. LÄS MER

  5. 9. Metoder att välja korrektioner vid fuktberäkningar med variabelt utomhusklimat

    Författare :Eva Harderup; Avdelningen för Byggnadsfysik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; moisture flow; Moisture; numerical modelling; calculation model; moisture distribution; non-linear moisture flow; external climate; moisture calculations; corrections; Building construction; periodic boundary condition; reference year; Byggnadsteknik;

    Sammanfattning : Determination of the design conditions for moisture resistance requires in a Moisture Design number of different moisture calculations to be made in order to determine the moisture status within, or on the surface of, a structure. The objective of this work has been to ascertain how to allow for variations in climate data in order to be able to determine the most unfavourable moisture status likely to be encountered during the life of a building. LÄS MER

  7. 10. Numerical Simulations of Plasmonic Nanostructures

    Författare :Joan Alegret; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nanoholes; DDA; Green s tensor; nanostructures; surface plasmons;

    Sammanfattning : This thesis focuses on the study of metallic nanostructures that support plasmons. Special emphasis is devoted to two specific numerical methods that allow us to predict plasmon characteristics: the discrete dipole approximation (DDA) and the Green's tensor (GT) method. LÄS MER