In the following, we will present an algorithm to perform adaptive free surface simulations with the lattice Boltzmann method (LBM) on machines with shared and distributed memory architectures. Performance results for different test cases and architectures will be given. The algorithm for parallelization yields a high performance, and can be combined with the adaptive LBM simulations. Moreover,...

Hybrid free-surface flows past disturbances in a two-dimensional channel are identified and studied. The fluid is assumed to be inviscid and incompressible, and the flow to be steady and irrotational. The disturbances consist of a step in the bottom of the channel and a flat object lying on the free-surface (e.g., a sluice gate). A weakly nonlinear one-dimensional analysis is used to classify t...

We will present an algorithm to handle moving and deforming objects for free surface fluid simulations with the lattice Boltzmann method (LBM). To achieve this we extend methods available for flows without a free surface to enables simulations of moving objects with varying surface roughness, two-way coupled interaction and improved mass conservation. We furthermore show how to efficiently init...

We study numerical approximations for geometric evolution equations arising as gradient flows for energy functionals that are quadratic in the principal curvatures of a two-dimensional surface. Beside the well-known Willmore and Helfrich flows we will also consider flows involving the Gaussian curvature of the surface. Boundary conditions for these flows are highly nonlinear, and we use a varia...

Over the past several years, as part of the Advanced Power Extraction (APEX) project, liquid metal magnetohydrodynamic (MHD) film and jet flows have been modeled using the assumption of axisymmetry to simplify the governing equations to a more tractable two-dimensional (2D) form. The results of these 2D simulations as they pertain to liquid wall and divertor flows is presented here. The effect ...

Aspects of a method for 3D finite element computation of unsteady, incompressible freesurface flow are presented. The approach is based on the Deformable-Spatial-Domain/ Stabilized Space-Time (DSD/SST) finite element formulation, which takes automatically into account the deformation of the elements in response to the motion of the free surface. The free-surface elevation is governed by a kinem...

Viscoelasticity can dramatically exacerbate free surface flow instabilities. It is shown here that this destabilization arises, at least in part, from the combination of large tangential tension and curvature along a concave free surface. Tension and curvature generically lead to an unstable stress gradient at the free surface; a perturbation that locally thickens a fluid layer leads to a local...

The continuum surface force (CSF) method has been extensively employed in the volume-of-fluid (VOF), level set (LS) and front tracking methods to model the surface tension force. It is a robust method requiring relatively easy implementation. However, it is known to generate spurious currents near the interface, which may lead to disastrous interface instabilities and failures of grid convergen...

Free surface potential flows past surfboards and sluice gates are considered. The problem is solved numerically by boundary integral equation methods. In addition weakly nonlinear solutions are presented. It is shown among the six possible types of steady flows, only three exist. The physical relevance of these solutions is discussed in terms of the radiation condition (which requires that ther...

In this paper, the application of a new robust and accurate SPH scheme proposed by Ferrari et al. [1] is presented. It provides good accuracy for computing complex 3D non-hydrostatic free surface flows. This has been assesed by the comparison of the numerical solutions of dam-break and impact-wave problems against experimental data and reference solutions. Moreover, to improve considerably the ...