A gallery illustrating a few of the capabilities of Diablo is provided below.  All simulations shown below by John Taylor using Diablo.

 

Rayleigh-Taylor Instability (unstable density gradient with no shear)

Warm fluid (red) is placed under more dense cold fluid (white) with a slightly perturbed interface.  The fluid is initially at rest and thus has potential energy, but no kinetic energy.  As time progresses, potential energy is transfered to kinetic energy and the two fluids mix.

Kelvin-Helmholtz Instability (shear layer with stable density gradient)

Dense fluid (white) is placed under less dense fluid (blue) in a stable density gradient, with the fluid above initially moving horizontally over the fluid below.  This situation often occurs at the tops of clouds.  An instability develops at the interface, yielding a “fluffy” cloud edge.

Shear layer with unstable density gradient

Warm fluid (red) is placed under cold fluid (blue) in a shear flow.  The kinetic energy due to the shear and the potential energy due to the unstable density gradient combine to result in vigorous turbulent mixing.

Stratified Bottom Ekman Layer (stable density gradient, shear + Coriolis)

Steady flow in geostrophic balance (pressure gradient balances Coriolis force) flows over a flat wall.  Near the wall where molecular and turbulent viscosity are significant, the flow turns in the direction of the pressure gradient, forming an Ekman spiral. Instantaneous streamlines illustrate the unsteady nature of the turbulent Ekman layer. Color indicates the temperature field, with red corresponding to warm fluid. An isosurface is drawn at a constant horizontal velocity magnitude and shows the low-speed streaks that are aligned with the surface stress.