Sökning: "Scaling dispersion"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden Scaling dispersion.

  1. 1. Theoretical Investigation into Longitudinal Dispersion in Natural Rivers — A Scaling Dispersion Model

    Författare :Zhi-Qiang Deng; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; soil mechanics; Väg- och vattenbyggnadsteknik; Environmental technology; pollution control; Miljöteknik; kontroll av utsläpp; offshore technology; hydraulic engineering; Civil engineering; Scaling dispersion.; Parameter estimation; Numerical scheme; Dispersion coefficient; Natural river;

    Sammanfattning : Using a broad variety of scientific methods this dissertation systematically investigates the fundamental mechanisms underlying the dispersion processes in natural rivers and their mathematical descriptions in a geometrical framework. Emphasis is on the geometrical variations and irregularities of a natural river and their scales. LÄS MER

  3. 2. Gas Mixing in a Circulating Fluidised Bed Boiler

    Författare :Johan Sternéus; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; circulating fluidized bed; gas mixing; tracer; boiler; dispersion; scaling; turbulence; two-phase flow; fluidization;

    Sammanfattning : The present thesis is a study on the gas-mixing behaviour in a circulating fluidised bed (CFB) boiler. The aim is to describe how gas is spread in different regions of a CFB furnace and to explain variations in the mixing rate under different operating conditions. LÄS MER

  4. 3. Unsaturated Solute Transport in a Semiarid Catchment - Nonlinear Analyses and Modelling

    Författare :Pernilla Öhrström; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; teknisk geografi; Hydrogeologi; teknisk geologi; unsaturated zone; Hydrogeology; geographical and geological engineering; solute transport; scaling; soils; semiarid regions; heterogeneity; preferential flow; fractals;

    Sammanfattning : Unsaturated solute transport is highly variable and therefore difficult to predict. In semi-arid areas, where water resources are limited, the presence of macropores is of great importance for crop production. The bromide ion (Br-) and dye tracers are useful for studies of water movement. LÄS MER

  5. 4. Scaling effects and homogenization of reaction-diffusion problems with nonlinear drift

    Författare :Vishnu Raveendran; Adrian Muntean; Irina Pettersson; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; homogenization; asymptotic expansion with drift; two-scale convergence with drift; effective transmission condition; dimension reduction; two-scale system; nonlinear dispersion; Matematik; Mathematics;

    Sammanfattning : We study the periodic homogenization of reaction-diffusion problems with nonlinear drift describing the transport of interacting particles in composite materials. The microscopic model is derived as the hydrodynamic limit of a totally asymmetric simple exclusion process for a population of interacting particles crossing a domain with obstacles. LÄS MER

  7. 5. On the Influence of Mixing and Scaling-Up in Semi-Batch Reaction Crystallization

    Författare :Marika Torbacke; KTH; []
    Nyckelord :reaction crystallization; precipitation; benzoic acid; macromixing; mesomixing; micromixing; semi-batch; loop reactor; backmixing; colour experiments; scaling-up;

    Sammanfattning : Semi-batch crystallization experiments have been performedboth in a loop reactor and in stirred tank reactors.Hydrochloric acid was fed to a stirred solution of sodiumbenzoate, and benzoic acid immediately formed. Benzoic acid isformed in excess of the solubility making the solutionsupersaturated.The loop reactor is U-shaped. LÄS MER