A drawback of the Smoothed Particle Hydrodynamics (SPH) method is its computational effort. An intuitive way to reduce the calculation time, is to use SPH only in parts of the problem domain where it is necessary, e.g. in a region where interfaces are present, because of the advantages of SPH for multiphase flow. In other parts of the problem domain, e.g. in a region of simple flow, a cheap met...

We present a simple and efficient fluid/solid coupling algorithm in two-spatial dimensions. In particular, we consider the numerical approximation of the Navier-Stokes equations on irregular domains and propose a novel approach for solving the projection step with Neumann boundary conditions on arbitrary shaped objects. This method is straightforward to implement and leads to a symmetric positi...

The semiconductor Boltzmann equation with elastic collisions as the dominating scattering eeects is considered. For the corresponding uid limit, the spherical harmonics expansion model, kinetic boundary layers are analyzed and higher order accurate boundary conditions are constructed. In a further step, boundary value problems for the energy transport model and the drift-diiusion model are deri...

From algal suspensions to magma upwellings, one finds jets which exhibit complex symmetry-breaking instabilities as they are decelerated by their surroundings. We consider here a model system--a saline jet descending through a salinity gradient--which produces dynamics unlike those of standard momentum jets or plumes. The jet coils like a corkscrew within a conduit of viscously entrained fluid,...

The simulation of multi-physics scenarios, in particular fluid-structure interaction has gained more and more importance in the last years due to increasing accuracy requirements for a large range of applications from biomedical fields to technical design problems. At the same time, this type of simulation has become feasible due to the increased computing power of modern supercomputers. Note t...

This paper is a continuation of earlier work [6] in which we presented an automatic domain decomposition method for the solution of gas dynamics problems which require a localized resolution of the kinetic scale. The basic idea is to couple the macroscopic hydrodynamics model and the microscopic kinetic model through a buffer zone in which both equations are solved. Discontinuities or sharp gra...

We establish in a direct manner that the steady state distribution of Markovian fluid flow models can be obtained from a quasi birth and death queue. This is accomplished through the construction of the processes on a common probability space and the demonstration of a distributional coupling relation between them. The results here provide an interpretation for the quasi-birth-and-death process...

We have coupled the three-dimensional solver for the two-phase incompressible Navier-Stokes equations NaSt3DGPF with Autodesk Maya. Maya is the industry standard software framework for the creation of three-dimensional animations. The parallel level-set-based fluid solver NaSt3DGPF simulates the interaction of two fluids like air and water. It uses high-order finite difference discretization me...

The coupled mechanics of fluid-filled granular media controls the physics of many Earth systems such as saturated soils, fault gouge, and landslide shear zones. It is well established that when the pore fluid pressure rises, the shear resistance of fluid-filled granular systems decreases, and as a result catastrophic events such as soil liquefaction, earthquakes, and accelerating landslides may...