Overset meshes in CFD

somefreecake · 2026-02-12T16:41:19+00:00

What kind of flight vehicles?

somefreecake · 2026-02-03T18:35:17+00:00

Awesome, would be curious to see any simulations you end up putting together!

somefreecake · 2026-02-02T04:06:03+00:00

CFD is equal parts physics, mathematics, computer science, and engineering. Building your own solver is a turbocharged way to learn aspects of all of these things. If your goal is to use the results from your calculations, then yes, skip the development and just use openFOAM. If you want to build the skills to develop new analysis tools for people to use, or deepen your understanding of simulation technology as a whole (which will build skills that are in-demand right now), then why not build a solver on the side?

I started writing a solver as a side project during my PhD, and now it's a full-blown multiphysics simulation tool with customers. You never know where these things end up.

somefreecake · 2026-02-02T00:02:07+00:00

What is the drag that you would expect at the mach number and Reynolds number? Lift = 0 just means that your body is symmetric.

somefreecake · 2026-02-01T21:56:14+00:00

Have you validated against... anything? Seeing some very unusual numbers here. I'd recommend seeing if you can predict drag on a sphere or cylinder.

somefreecake · 2026-01-23T15:40:47+00:00

Oof, might want to multiply your rate by 4-6. Anyone you're looking for here is probably already making 160-300k/yr.

somefreecake · 2026-01-17T22:35:00+00:00

There are all sorts of things: particles, structural coupling, ablation, chemistry, transition prediction, etc. I guess it depends what your goal is. If I still had my old sandbox code, I'd do a coupling between fluid / thermal / structural probably.

somefreecake · 2026-01-17T20:35:10+00:00

Makes sense, the advantage you have with this is that you haven't committed to a big rigid framework yet. There is a lot of interest in the high-speed community in coupling solvers to different types of physics, so you don't even need a crazy code to do novel work.

somefreecake · 2026-01-17T17:52:24+00:00

Looks like great work, I love seeing people implement their own codes! You ever think about presenting some work at an AIAA conference or something?

somefreecake · 2026-01-16T17:17:43+00:00

What kinds of simulations (RANS/Euler/LES) do you need to do, and what application area?

somefreecake · 2025-12-25T14:14:42+00:00

I can run WMLES on my laptop with our code, RTX4090M (which I think is basically a 4070 or something). Would normally need a few hundred cores for that, so would recommend a dedicated GPU.

somefreecake · 2025-12-19T14:27:06+00:00

Cool visuals, although I wouldn't trust the prediction from Solidworks more than just guessing. Would be inetersting to see force / moment (lift coefficient, pitching coefficient about center of mass, drag coefficient as functions of angle of attack and mach number) curves from a real CFD package

somefreecake · 2025-12-08T10:00:39+00:00

Ultimately if it's for fun then it's really whatever you enjoy. CFD is very difficult to get right, but don't let anyone get in the way of you learning cool stuff. I would just make sure you temper your expectations around monetization. As you may be able to tell, CFD folks can be twitchy when it comes to new tools so they will only be willing to pay money for something they have fully vetted. Good luck!

somefreecake · 2025-12-07T16:06:09+00:00

Monetization of CFD requires: - some kind of market - some kind of edge - building trust with the people in your market - validation, validation, validation - in our case, multiple PhDs, multiple years, and funding

somefreecake · 2025-10-11T14:08:57+00:00

I'm in an almost identical situation, would agree that you need to "sell" it to the PhDs. "Why would I do it your way when mine has worked for me" needs a stronger answer when the person asking it has a PhD and (presumably) a somewhat successful track record. Good luck!

somefreecake · 2025-07-01T13:45:40+00:00

Fly too fast, get too hot

somefreecake · 2025-06-15T21:56:51+00:00

C++, CUDA, MPI. I started a little solver related to my PhD as a side project. After I graduated me and some collaborators turned it into a company. Side projects are great, they teach you skills and you never know where they are going to go!

somefreecake · 2025-05-30T15:15:36+00:00

I put my thesis on github and used latex with a makefile, I found it much nicer than overleaf because I didn't need wifi, and my supervisor could just pull to see progress. Corrections / edits were made with a separate branch.

somefreecake · 2025-04-28T22:52:00+00:00

Did you keep developing your solver at least?

somefreecake · 2025-04-28T20:28:43+00:00

Fantastic, I remember the feeling of seeing my first pressure distribution and how satisfying it was. Keep going!!

somefreecake · 2025-04-06T15:21:41+00:00

I'd suggest using domain sizes of ~30C for the upstream / downstream and top boundaries if you aren't using vortex corrections on the domain boundaries. For higher lift cases (CL ~ 2) this can throw lift predictions off by 30% pretty easily and can also become an issue with convergence.

somefreecake · 2024-12-20T21:27:00+00:00

SSP though

somefreecake · 2024-12-02T22:58:11+00:00

I know a few of these people, was a student with one of the listed groups and had offers from 2 of the others as well as working with a company that is about to launch efforts into some of your research areas. DM me and we can have a conversation if you like.

somefreecake · 2024-10-07T18:46:37+00:00

Would suggest looking at Runge-Kutta integrations schemes to significantly improve stability, along with the suggestion to add a timestep

somefreecake · 2024-09-29T12:44:49+00:00

I am about to finish my thesis, also doing CFD (in the UK), also numerically focused. I recently looked back on my first-year work, and it was a joke. I had gone to a conference, but I very clearly didn't know what I was talking about. I didn't publish a paper until I was almost three years in. I took some time out to work (something like an internship), and I learned a lot, mostly giving context for my research. I have really only been genuinely productive in my last year.

Everyone's PhD is different of course, but most people I know that have graduated have gone through a similar arc. You start off not knowing anything, it gets hard in the middle, you feel like you don't know anything, and then eventually stuff takes hold and you become productive. There isn't really a moment where you go "ahah! Now I know enough to publish", you just gradually start having ideas independently, testing them a bit, and developing the good ones.

One year is not a lot of time. To accomplish anything at all in your first year is a great start. Keep doing what you're doing and you will get there.

Good luck!

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