**03 Feb 2015 · Compressible Euler flow** [news]

A numerically challenging problem to solve is compressible flow. This primarily has to do with the hyperbolic nature of the problem. The movie shows a finite-element solution of a two-dimensional extension of the SOD shock-tube benchmark. A triangular region of high pressure is released into a region of low pressure. [...]

**23 Jan 2015 · Torsional buckling** [news]

In elastic theory, the infinitesimal strain formulation is sufficiently accurate to approximate small elastic deformations.
For larger deformations, however, the non-linear, finite-strain formulation should be considered.
The first figure shows a large elastic deformation using the infinitesimal strain formulation (*left*) and
finite-strain formulation (*right*). The color represents *Von Mises* stress. [...]

**01 Jan 2015 · Happy New Year** [news]

HvZ Computational Engineering wishes everyone a happy, healthy and successful 2015! [...]

**01 Dec 2014 · Kelvin-Helmholtz instabilities** [news]

When a single fluid contains layers that move with different velocities, vortices are formed on the interface. This phenomenon is known as Kelvin-Helmholtz instability. [...]

**01 Nov 2014 · Unmixing with Cahn-Hilliard** [news]

A complicated topic in computer simulation is the area of multi-species flow, in particular, the interface between the two species.
An interesting approach to facilitate the numerical difficulty in dealing with the interfaces, is by solving an additional problem known as the * Cahn-Hilliard equation.*
Cahn-Hilliard is a so-called * diffuse interface model * and describes the interface not as a discontinuity but rather as a smooth transition between both species. [...]