Sökning: "Boltzmann equation"

Visar resultat 6 - 10 av 38 avhandlingar innehållade orden Boltzmann equation.

1. 6. Stability and Exponential Convergence for the Boltzmann Equation

   Författare :Bernt Wennberg; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis is devoted to the long-time behaviour of the nonlinear Boltzmann equation for a class of molecular interactions, including inverse power laws for hard potentials. It has been known for some time now, that under natural conditions on the initial data, the space homogeneous Boltzmann equation possesses a unique, global solution, and that this solution tends strongly to the equilibrium distribution as time tends to infinity. LÄS MER

3. 7. Some numerical and analytical methods for equations of wave propagation and kinetic theory

   Författare :Eva Mossberg; Alexander Bobylev; Giovanni Russo; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; wave propagation; finite difference metods high order methods; Landau-Fokker-Planck equation; Monte-Carlo simulations; Boltzmann equation; hard sphere model; eigenvalue problem; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

   Sammanfattning : This thesis consists of two different parts, related to two different fields in mathematical physics: wave propagation and kinetic theory of gases. Various mathematical and computational problems for equations from these areas are treated. LÄS MER

4. 8. Electrostatic Interactions in Complex Liquids : A Thermodynamic Analysis Based on the Poisson-Boltzmann Equation and the Flexible Surface Model

   Författare :Ingemar Carlsson; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AOT; AerosolOT; ionic surfactant; spontaneous curvature; bending modulus; bending energy; Helfrich curvature energy; fluid membrane; complex liquid; flexible surface model; micelle; counterion; Poisson-Boltzmann equation; cell model; L3 phase; sponge phas; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : The aim of this study was to analyse physico-chemical properties of some complex liquids using the Poisson-Boltzmann (PB) cell model; to extend the theory to cover bilayer systems with complex global geometry; finally to apply this new extended model to such bilayer systems. The PB cell model provides a practical tool to examine counterion association and phase behaviour for structures of simple geometries; cylindrical and spherical. LÄS MER

5. 9. Some non-linear geometric and kinetic evolutions and their approximations

   Författare :Richards Grzhibovskis; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; curvature flow; Willmore flow; convolution-thresholding; homothetic geometric flows; Boltzmann equation; deterministic methods; non-uniform grids; curvature flow;

   Sammanfattning : This thesis deals with three non-linear evolution problems: mean curvature flow, Willmore flow, and the evolution of solutions to the space homogeneous Boltzmann equation. Generalized mean curvature flows are also considered. A major part of the study focuses on the construction of approximations to these evolutions. LÄS MER

7. 10. Discrete Velocity Models and Half-Space Problems

   Författare :Niclas Bernhoff; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boltzmann equation; discrete velocity models; half-space problems; Matematik; Mathematics;

   Sammanfattning : We study some questions related to discrete velocity models (DVMs) of the Boltzmann equation. In the case of plane stationary problems the typical DVM reduces to a dynamical system (system of ODEs). Properties of such systems are studied in this paper in the most general case. LÄS MER