Sökning: "atmospheric boundary layer ABL"

Hittade 4 uppsatser innehållade orden atmospheric boundary layer ABL.

  1. 1. Verification and validation of the implementation of an Algebraic Reynolds-Stress Model for stratified boundary layers

    Master-uppsats, KTH/Teknisk mekanik

    Författare :Martina Formichetti; [2022]
    Nyckelord :Atmospheric boundary layer; turbulence modelling; stratified flows; eddy viscosity; eddy diffusivity;

    Sammanfattning : This thesis studies the implementation of an Explicit Algebraic Reynolds-Stress Model(EARSM) for Atmospheric Boundary Layer (ABL) in an open source ComputationalFluid Dynamics (CFD) software, OpenFOAM, following the guidance provided by thewind company ENERCON that aims to make use of this novel model to improvesites’ wind-field predictions. After carefully implementing the model in OpenFOAM,the EARSM implementation is verified and validated by testing it with a stratifiedCouette flow case. LÄS MER

  3. 2. Evaluation of a stochastic model of coherent turbulent structures for atmospheric particle deposition applications

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Luft-, vatten- och landskapslära

    Författare :Andreas Eriksson; [2022]
    Nyckelord :atmospheric dispersion; particle deposition; k-epsilon; RANS; lagrangian particle model; stochastic particle model; OpenFOAM; SIMPLE algorithm; ABL; atmospheric boundary layer; neutral boundary layer; coherent turbulent structures;

    Sammanfattning : In this thesis, we have evaluated a stochastic Lagrangian model for computing particle deposition rates with prospects to use for atmospheric deposition applications.  The model is one-dimensional and models the particle dynamics in the boundary layers near walls and obstacles by simulating the coherent turbulent structures and Brownian motion governing the wall-normal transport. LÄS MER

  4. 3. Characterisation of Low-Level Jets and their Influence on Low-Level Clouds over the Baltic Sea; Östergarnsholm Observatory, Sweden

    Kandidat-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Förbränningsfysik

    Författare :Johan Lundberg; [2021]
    Nyckelord :Low-level jets; Low-level clouds; LLJs; LLCs; Boundary layer; ABL; CBH; Lidar; Ceilometer; Turbulent intensity; Physics and Astronomy;

    Sammanfattning : In this study, about two years of data from Östergarnsholm in the Baltic Sea are used to analyse offshore low-level clouds (LLCs) influenced by low-level jets (LLJs) in the marine atmospheric boundary layer. The LLJs are passages of strong horizontal winds near the surface and are measured using a Doppler LiDAR, which provides information about the wind speed and wind direction up to 300 meters. LÄS MER

  5. 4. Crosswind assessment of trains on different ground configurations

    Master-uppsats, KTH/Järnvägsteknik

    Författare :Nachiyappan Venkatasalam; [2013]
    Nyckelord :Crosswind; ICE3; true flat ground TFG ; single track ballast and rail STBR ; atmospheric boundary layer ABL ; AeroTRAIN; CFD.;

    Sammanfattning : Cross wind analysis is one of the important safety measures for rail vehicle certification. The objective of this study is to identify which vehicle certification ground setup, true flat ground (TFG) or single track ballast and rail (STBR) represents a more realistic ground setup with atmospheric boundary layer (ABL) wind inlet and also to represent an embankment scenario. LÄS MER