Sökning: "Lagrangian dispersion model"

Visar resultat 1 - 5 av 7 uppsatser innehållade orden Lagrangian dispersion model.

  1. 1. 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

  3. 2. Kernel density estimators as a tool for atmospheric dispersion models

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Daniel Egelrud; [2021]
    Nyckelord :Particle model; LPELLO; kernel density estimation; field of concentration; post-processing;

    Sammanfattning : Lagrangian particle models are useful for modelling pollutants in the atmosphere. They simulate the spread of pollutants by modelling trajectories of individual particles. However, to be useful, these models require a density estimate. The standard method to use has been boxcounting, but kernel density estimator (KDE) is an alternative. LÄS MER

  4. 3. Electromagnetic form factors of the Sigma*-Lambda transition

    Master-uppsats, Uppsala universitet/Kärnfysik

    Författare :Timea Vitos; [2019]
    Nyckelord :hyperon form factors; dispersion relations; anomalous cuts;

    Sammanfattning : We introduce and examine the analytic properties of the three electromagnetic transition form factors of the Sigma*-Lambda hyperon transition. In the first part of the thesis, we discuss the interaction Lagrangian for the hyperons at hand. LÄS MER

  5. 4. Updating bounds on the low-energy constants of Chiral Perturbation Theory from exact bounds on amplitudes

    Master-uppsats, Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation; Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

    Författare :Benjamin Alvarez; [2016]
    Nyckelord :Coupling constants; meson-meson scattering; Chiral perturbation theory; constraints.; Physics and Astronomy;

    Sammanfattning : Chiral perturbation theory is an efficient effective theory to describe meson-meson scattering at low energy. An effective theory naturally introduces low energy constants and they are used, for example, to solve the ultraviolet divergences. LÄS MER

  7. 5. Boundary conditions for modeling deposition in a stochastic Lagrangian particle model

    Master-uppsats, Umeå universitet/Institutionen för fysik

    Författare :Tobias Jonsson; [2015]
    Nyckelord :Lagrangian dispersion model; Boundary behavior; time step;

    Sammanfattning : The Swedish defence agency (FOI) has developed a particle model (called Pello) that simulates the dispersion of aerosols and gases. At the boundaries, such as the ground, the particles can either reflect back into the domain (the atmosphere) or be absorbed. LÄS MER