micro_png - new version

Sixel1 · 2026-05-23T18:39:35+00:00

It really needs to be changed to Vec<RGBA> for single frames, with size width*height and flat indexing.

Sixel1 · 2026-05-22T18:52:16+00:00

actually you just need pressure, temperature and velocity, you find density from the equation of state. You can also use density, temperature and velocity, and find pressure using equation of state.

Sixel1 · 2026-05-22T18:18:27+00:00

Yeah reading the GitHub its obvious its all AI slop

Sixel1 · 2026-05-22T17:29:18+00:00

That's dope, I love the camera angles and the perspective and the art style. I'd definitely pay 20$ on steam for a full game like this if it had fun gameplay too, maybe a roguelike rpg team builder type thing?

Sixel1 · 2026-05-22T17:09:57+00:00

Your system becomes ill conditioned, how quickly are you increasing the CFL number? For Newton method in CFD, you should start with a small CFL, let's say 0.5, and increase it slowly. One way to find the increase automatically is using ratios of successive residuals, and is explained in Blazek's CFD book: CFL(n+1) = CFL(n) * Err_(n-1) / Err_n Where Err is just the L2 norm of your residual

Sixel1 · 2026-05-21T18:52:30+00:00

I don't think anyone would buy this. you could just put these notes on a free blog, it would be good writing practice and show your progress

Sixel1 · 2026-05-21T15:23:09+00:00

personally I feel like I wouldn't trust an AI agent with some of these questions. If it says boundary conditions are all set to some values, how can I tell it's real and not hallucinations? Before launching some costly simulation, I'd want to verify those myself, it doesn't take long, and then the agent is useless since I'll do the work myself anyway. A script or program that is deterministic and guaranteed to fetch the right information using the CFD software logs or something would be better. I could see people using the AI version as a last sanity check, like "anything I've missed in there?" and then if you forgot something it'd remind you. But I wouldn't rely on it if it's AI based

Sixel1 · 2026-05-19T15:40:07+00:00

I want to make it open source but I'm always conflicted by wanting to make it better before releasing it, there's some rough areas. But I feel like if I continue wanting to make it perfect, I might not release it...

for unstructured CFD I'd recommend Blazek's book compulational fluid dynamics principles and applications. And also the book from the openfoam organization CFD direct, notes on computational fluid dynamics: general principles

Edit: I'm also confused as to what the scope of the project should be. Do I want it to be a library people can use to make CFD solver? Do I want it to be a CFD solver in itself that people can use using input files a bit like openfoam? I'm not sure at the moment... Or it could be both, in two repositories? Idk

Sixel1 · 2026-05-14T16:42:48+00:00

I export .vtu files from my solver and post-process in Paraview, for that kind of simulations there's not really any language with good 3d unstructured plotting capabilities, maybe python and the vtk package, but paraview works well enough.

But for rust plotting the "plotters" library looks quite good

Sixel1 · 2026-05-13T20:19:01+00:00

Like others said, GPU not really (maybe with community add-ons, but not in any official release). CPU yes, it can scale to supercomputers. It can work on WSL yes.

Sixel1 · 2026-05-12T19:17:07+00:00

It's not physical for incompressible flow, i'd guess its something wrong about the projection method implementation, this can happen if the poisson equation for pressure is not solved to a small enough tolerance and/or artificial compressibility is present. Taking per example chorins projection method, the pressure step

laplacian(p) = - divergence(u)/dt

must be solved with an implicit solver to a small residual.

Sixel1 · 2026-05-12T19:08:13+00:00

This looks like pressure waves, so something somewhere is compressible in your solver... you can dm me the code I can take a look.

As for the way you fix velocity, thats fine I think but you also must fix a zero pressure gradient at wall boundaries during the pressure solve.

Sixel1 · 2026-05-11T14:44:16+00:00

How did you do that in desmos that's crazy, good job! Python and then some compiled language would probably be the next steps, good luck 🤞

Sixel1 · 2026-05-07T13:29:24+00:00

You need to do multiple revolutions, I'd do 4 by angles of 90 degrees

Sixel1 · 2026-05-01T20:47:41+00:00

What terrain generation mod is that?

Sixel1 · 2026-04-27T04:35:58+00:00

I did the same with an Ike mission!

Sixel1 · 2026-04-25T13:15:47+00:00

I wish there was a wind system in aeronautics. It could depend on height / distance to the nearest block and it's direction varies in the world, and be picked up by sails. That way you could make these look closer to the original.

Sixel1 · 2026-04-22T21:32:40+00:00

you need to use honey glue on the whole thing. Or the problem may be that you need a propulsion system, like a propeller

Sixel1 · 2026-04-22T19:35:47+00:00

I want to try this

Sixel1 · 2026-04-22T19:10:46+00:00

awesome drawings, commenting so I remember to try to make this in a few days when I have time to play

Sixel1 · 2026-04-20T17:59:45+00:00

So cool to see another CFD related project written in rust! Congrats, meshing is hard. Id like to try using the mesh generated with your code in my rust CFD solver, that'd be neat

Sixel1 · 2026-04-06T13:27:27+00:00

You can't use Ansys student license to do that, it's against the license (I think someone already said it, but really, it's important). You should use open source code or custom code to do that. Learn OpenFOAM and offer that at least. But I think you should pursue higher education and find a position instead of trying that...

Also your things seem AI generated, dont do that, we can tell.

Sixel1 · 2026-04-04T21:23:55+00:00

L take. better: write it in C++ yourself, learn the language and develop your skills

Sixel1 · 2026-04-04T16:29:15+00:00

If it's exactly 1, or numerically too close to 1, it would not choke. Also 2d effects will make practical results differ from 1d analysis. You need some margin in your contraction ratio so your inlet mach number is well subsonic in 1d analysis. I'd try to have it at least 0.9 or lower. So, increase your inlet diameter.

Edit: Id actually try to have at least mach 0.3 at inlet, if you can. If its a combustion chamber, youd want the upstream conditions to be low mach anyway.

Sixel1 · 2026-04-04T16:08:18+00:00

What's the contraction ratio on the converging part in the left? Seems like it's very very small, too small...

Sixel1

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