A small turbulent velocity script

[fjebaker]

Yields the following figures:

[phajy]

Thanks, @fjebaker - this looks great! @katebolam and @jj-auer you should be able to see the section of the code where you can put in a prescription for the turbulence.

This reminded me that perhaps §2 of Accretion disc turbulence and the X-ray power spectra of black hole high states (1995) by Nowak & Wagoner might be worth a read where they describe the "basics of disc turbulence".

However, I would recommend starting with a pretty simple description just to get things working and to make some nice plots for your presentation. You might also want to investigate how to use Gradus.jl with this new velocity field (we can talk about this at the next project meeting).

One possible Julia package for generating noise could be CoherentNoise.jl. Alternatively, you could write your own, which might become necessary to really understand how the noise is being generated and to ensure it has the desired properties. Any other suggestions, @fjebaker?

Happy for this to be merged once Kate and Joschka have had a look.

[fjebaker]

Oh cool so the next step of improvement I was going to reveal is that Perlin noise is fine for an approximation, but actual turbulent velocity structures are likely more akin to different noise patterns, and was going to suggest doing a dig in the literature and trying things like fractiona Brownian motion, and see what the effects of these noise patterns are. I didn't know about CoherentNoise.jl, but that package looks like it would make the next step much more straight forward!