It's not just Google that can doodle. The Computational Fluid Dynamics (CFD) community on occasion has also been known to embrace its whimsy side, especially during holidays, and so I give you a CFD doodle. For fluid dynamicists (or at least this one) the snow globe has always had a special attraction and if one is good then four has to be awesome, right?

Multiple Interconnected Snow Globes Flow Animation

Design

Having decided to interconnect a number of snow globes, then the conversation moves on to how many and in what configuration. Then with a flash of inspiration the plan comes together; it has to be a tetrahedron configuration, given its ubiquitous use in CFD volume meshes. The four nodes of the tetrahedron will be the globes and the tetrahedron edges will be the pipes to interconnect the globes. In each globe we need a holiday symbol, so I settled on a simple festive tree.

Multiple Interconnected Snow Globes Geometry

The geometry is relatively straightforward - the only complication is to make sure I have the correct angles for a regular tetrahedron.

Rather than have to keep shaking the snow globes to reveal their magic, I thought it would be more in keeping with the 'engineer does snow globe whimsy' to outfit the system with a couple of fans. This enhanced magic ensures there is always something moving - hands free.

Multiple Interconnected Snow Globes Mesh

Visualization

I finalized the effect with the release of massless particles that then circulate through the passages, around the globes, and meander through the trees.

Multiple Interconnected Snow Globes Particles

Final Word

Although this is a special CFD doodle for the holidays, remember that CFD is good for doodles (sorry, work) all year round.

Notes

• The geometry was created in Caedium Professional.
• The CFD simulation was performed using the incompressible, steady-state RANS solver in Caedium Professional with the k-omega SST turbulence model.