Sökning: "mean curvature flow"
Visar resultat 1 - 5 av 13 avhandlingar innehållade orden mean curvature flow.
1. On one approximation scheme for generalised mean curvature flow
Sammanfattning : .... LÄS MER
2. Some non-linear geometric and kinetic evolutions and their approximations
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
3. Vortices in turbulent curved pipe flow-rocking, rolling and pulsating motions
Sammanfattning : This thesis is motivated by the necessity to understand the flow structure of turbulent flows in bends encountered in many technical applications such as heat exchangers, nuclear reactors and internal combustion engines. Flows in bends are characterised by strong secondary motions in terms of counter-rotating vortices (Dean cells) set up by a centrifugal instability. LÄS MER
4. Finite element methods for surface problems
Sammanfattning : The purpose of this thesis is to further develop numerical methods for solving surface problems by utilizing tangential calculus and the trace finite element method. Direct computation on the surface is possible by the use of tangential calculus, in contrast to the classical approach of mapping 2D parametric surfaces to 3D surfaces by means of differential geometry operators. LÄS MER
5. Turbulence-resolving Simulations of Swirling Flows
Sammanfattning : A series of numerical investigations is undertaken using a wide range of turbulence mod-els including conventional and non-conventional URANS models, hybrid URANS-LESmethods and LES to capture a large variety of physical mechanisms that produce pres-sure pulsations in the swirling flows. The available knowledge about these pulsations,which are usual in hydropower, are still far from complete. LÄS MER