The interaction of moving fluids with particles is still only understood phenomenologically when the Reynolds number is not vanishing. I will present three different numerical studies all using the solver “fluent” which elucidate this issue from different points of view. On one hand, I will...

Sand-moving winds blowing from a constant direction in an area of high sand availability form transverse dunes, which have a fixed profile in the direction orthogonal to the wind. Here we show, by means of a linear stability analysis, that transverse dunes are intrinsically unstable. Any...