Sökning: "explicit algebraic Reynolds-stress models"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden explicit algebraic Reynolds-stress models.

  1. 1. Modelling of stably-stratified, convective and transitional atmospheric boundary layers using the explicit algebraic Reynolds-stress model

    Författare :Velibor Zeli; Gert Brethouwer; Arne V. Johansson; Stefan Wallin; Bert Holtslag; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmospheric turbulence; convective atmosphere; Reynolds-stress model; stably-stratified atmosphere; transitional atmosphere; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : The atmospheric boundary layer (ABL) is in continuous turbulent motion. The heating and cooling of the Earth’s surface drives mechanic and thermodynamic processes in the ABL through enhancing and damping of atmospheric turbulence. The surface forcing has a profound effect on the diurnal cycle of temperature,wind and related variables in the ABL. LÄS MER

  3. 2. Explicit algebraic turbulence modelling in buoyancy-affected shear flows

    Författare :Werner Lazeroms; Arne Johansson; Antti Hellsten; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Turbulent flows affected by buoyancy forces occur in a large amount of applica-tions, from heat transfer in industrial settings to the effects of stratification inEarth’s atmosphere. The two-way coupling between the Reynolds stresses andthe turbulent heat flux present in these flows poses a challenge in the searchfor an appropriate turbulence model. LÄS MER

  4. 3. Turbulence Modelling and Parallel Solver Development Relevant for Investigation of Gas Turbine Cooling Processes

    Författare :Rongguang Jia; Värmeöverföring; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal engineering; applied thermodynamics; Termisk teknik; termodynamik; large eddy simulation; Reynolds stress transport model; turbulence modelling; multi-block; parallel computing; Impingement cooling; ribbed surface;

    Sammanfattning : To enhance the performance of gas turbine engines, high top-cycle temperatures are desired. However, the temperature is limited by current materials. 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. Development and analysis of turbulence models for flows with strong curvature and rotation

    Författare :Olof Grundestam; KTH; []
    Nyckelord :Turbulence model; nonlinear modelling; streamline curvature; high-lift aerodynamics;

    Sammanfattning : An explicit algebraic Reynolds stress model (EARSM) based ona pressure strain rate model including terms tensoriallynonlinear in the mean velocity gradients is developed in orderto improve predictions for .ows with strong curvature and/orrotation. LÄS MER