Sökning: "Boundary conditions"
Visar resultat 11 - 15 av 860 avhandlingar innehållade orden Boundary conditions.
11. Mesoscale Processes over the Baltic Sea
Sammanfattning : The objective of this thesis is to study mesoscale processes above the Baltic Sea, which is a small, semi-enclosed sea where land-sea interaction may have a large impact on the offshore conditions. It is only the last tens of years that offshore research has become more popular, and one reason for this is the increasing offshore wind energy, which poses the need for accurate estimates of wind speed and turbulence conditions in the marine environment. LÄS MER
12. Boundary integral methods for Stokes flow : Quadrature techniques and fast Ewald methods
Sammanfattning : Fluid phenomena dominated by viscous effects can, in many cases, be modeled by the Stokes equations. The boundary integral form of the Stokes equations reduces the number of degrees of freedom in a numerical discretization by reformulating the three-dimensional problem to two-dimensional integral equations to be discretized over the boundaries of the domain. LÄS MER
13. Non-reflecting Boundary Conditions for Wave Propagation Problems
Sammanfattning : We consider two aspects of non-reflecting boundaryconditions for wave propagation problems. First we evaluate aproposed Perfectly Matched Layer (PML) method for thesimulation of advective acoustics. It is shown that theproposed PML becomes unstable for a certain combination ofparameters. A stabilizing procedure is proposed andimplemented. LÄS MER
14. Simulations of turbulent boundary layers with suction and pressure gradients
Sammanfattning : The focus of the present licentiate thesis is on the effect of suction and pressure gradients on turbulent boundary-layer flows, which are investigated separately through performing numerical simulations.The first part aims at assessing history and development effects on adverse pressure-gradient (APG) turbulent boundary layers (TBL). LÄS MER
15. Air mass boundary identification : improvement of precipitation phase determination in surface based modeling
Sammanfattning : Snowpack properties derived from hydrological models play an important role for many ecological, water resource, and climate applications; such as winter survival of plants, reindeer, small mammals and birds, avalanche hazards, glaciers and polar ice accumulation, growth of sea and lake ices, climate change, snow melt flooding etc. These hydrological models need accurate precipitation phase discrimination schemes to closely portray e. LÄS MER
