Sökning: "natural convection boundary layer"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden natural convection boundary layer.

  1. 1. DNS and LES of Turbulent Natural Convection Boundary Layer

    Författare :Darioush Gohari Barhaghi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DNS; free convection; LES; natural convection boundary layer; vertical cylinder;

    Sammanfattning : Turbulent natural convection boundary layers possess some special characteristicscompared to the other boundary layers.In order to study this kind of boundary layer, two powerful numerical methods,Direct Numerical Simulation or DNS and Large Eddy Simulation or LES,are used. LÄS MER

  3. 2. Turbulence Measurements in a Natural Convection Boundary Layer and a Swirling Jet

    Författare :Abolfazl Shiri; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swirl; constant current bridge; high Rayleigh number; natural convection; Jet; cold-wire thermometry; vertical cylinder; laser Doppler anemometry; turbulent boundary layers;

    Sammanfattning : Two sets of experimental measurement were carried out on an axisymmetric swirling jet flow and a natural convection boundary layer. In the first experiment, the far field of an incompressible swirling jet, discharged into a quiescent ambient has been studied using laser Doppler anemometry. LÄS MER

  4. 3. A Study of Turbulent Natural Convection Boundary Layers Using Large-Eddy Simulation

    Författare :Darioush Gohari Barhaghi; Chalmers tekniska högskola; []
    Nyckelord :natural convection boundary layer; DNS; LES; radiation heat transfer; free convection; cavity; vertical cylinder;

    Sammanfattning : The structure of turbulent natural convection boundary layers in differentgeometries and the effect of the buoyancy on a mixed convection boundarylayer are investigated. These geometries comprise a vertical finitecylinder, a vertical infinite channel, a cavity and a vertical finite channel. LÄS MER

  5. 4. Turbulence modelling applied to the atmospheric boundary layer

    Författare :Werner Lazeroms; Arne Johansson; Geert Brethouwer; Evgeni Fedorovich; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; turbulence; RANS models; explicit algebraic Reynolds-stress models; buoyancy; stable stratification; thermal convection; atmospheric boundary layer;

    Sammanfattning : Turbulent flows affected by buoyancy lie at the basis of many applications, both within engineering and the atmospheric sciences. A prominent example of such an application is the atmospheric boundary layer, the lowest layer of the atmosphere, in which many physical processes are heavily influenced by both stably stratified and convective turbulent transport. LÄS MER

  7. 5. Semi-Toeplitz preconditioning for linearized boundary layer problems

    Författare :Samuel Sundberg; Lina von Sydow; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

    Sammanfattning : We have defined and analyzed a semi-Toeplitz preconditioner for time-dependent and steady-state convection-diffusion problems. Analytic expressions for the eigenvalues of the preconditioned systems are obtained. LÄS MER