Parametric studies on the water impact of one and twin free-falling wedges by a Cartesian grid multiphase flow model

The water impact of one and twin free-falling wedges is numerically investigated by a Cartesian grid multiphase flow model. The effects of the drop velocity and the gap distance on the hydrodynamic behaviors are parametrically investigated. The numerical model involves a radial basis function ghost cell method (RBFGCM) for treating moving...

Detailed simulation of morphodynamics: 1. Hydrodynamic model

We present a three-dimensional high-resolution hydrodynamic model for unsteady incompressible flow over an evolving bed topography. This is achieved by using a multilevel Cartesian grid technique that allows the grid to be refined in high-gradient regions and in the vicinity of the river bed. The grid can be locally refined and adapted to the...

Computational modelling of small-scale river morphodynamics

Alluvial open channel beds often exhibit statistically periodic irregularities, known as dunes. Dunes have considerable effects on sediment transport and flow resistance. When growing during a flood, the dunes create more resistance and flood levels may rise significantly. Accurate prediction of dune properties therefore contributes to effective...

On the treatment of complex geometries in a Cartesian grid flow solver with the level set method

We present a new Cartesian grid method for the computation of incompressible viscous flows in irregular geometries. The irregular boundary is implicitly represented by its signed distance function (the level-set function) and, by using level-set calculus tools, we are able to preserve the Cartesian structure of the discretized Navier-Stokes...

Cartesian Discretisations for Fluid-Structure Interaction - Efficient Flow Solver

The simulation of multiphysical scenarios has become a more and more important task of scientific computing within the last years. Due to their simplicity compared to monolithic approaches (solving a unique model for the whole scenario), partitioned approaches are widespread. They allow for a reusage of existing and established solvers for the...

Cartesian Discretisations for Fluid-Structure Interaction - Consistent Forces

Hierarchical Cartesian grids such as those defined by spacetrees have proven to be useful in lots of simulation scenarios in spite of their frequently supposed difficulties concerning the approximation of complicated and changing geometries. One of their most important advantages is the simple, efficient and flexible interface they offer. Thus,...

Image-based method for the aerodynamic characteristics of a motor cycle

In this paper, a simple analysis method for flow simulations around a motor cycle is discussed based on CFD. In the practical CFD, most of the efforts are wasted for grid generations. The typical two types of grid are body-fitted grid and Cartesian grid. Body-fitted grid was often used for the flow calculation around the vehicle until today....

A three-dimensional fixed grid model for shallow-water flow

In this report the implementation and testing of a numerical model that is based on a Cartesian fixed grid in vertical direction is described. The model uses the shallow-water equations and accounts for effects of stratification. In stratified environments, the terrain-following 0-transformation, which is often used in shallow-watermodels, is...