Aerodynamics and hydrodynamics are both branches of fluid dynamics, the fluids in question obviously being air and water. But the difference with them lies mostly in their Reynold's Number. Particularly, if you scale your model accordingly between the different fluids w.r.t. each Reynold's Number, you'll find that the dynamics behave similarly. As in, you can test an airplane wing underwater and expect appropriate results.

Which I suppose means a hydrodynamic lobster could theoretically imply an aerodynamic lobster. I think.

[–] AEsheron 2 points 9 months ago

The short version is the two should be relatively closely related, most things that are one will likely be the other. Not always true, but a decent rule of thumb.

[–] SpaceNoodle 1 points 9 months ago

https://en.wikipedia.org/wiki/Hemaris_diffinis