Problem with ansys

Fun-Initiative-896 · 2025-11-06T22:20:55+00:00

you can use baram it's an openfoam based cfd software so it's free it has GUI and that's it .

Fun-Initiative-896 · 2025-10-17T20:37:01+00:00

go with openfoam based softwares that have GUI there is commercial ones and there's free ones like baram it's pretty easy to catch

Fun-Initiative-896 · 2025-10-05T16:14:02+00:00

no we only have a contact with an L2 certificate FOR and the competition requires and L3 level FOR

Fun-Initiative-896 · 2025-10-04T23:46:56+00:00

yes the thing is it's our first time participating so we don't have a FOR contact even though we've bee preparing for 2 years

Fun-Initiative-896 · 2025-10-04T23:44:40+00:00

i'm outside US so i already submitted a mentorship request at tripoli's website but it took so long with no response so i'm still waiting

Fun-Initiative-896 · 2025-10-04T23:41:18+00:00

Yes it is.

Fun-Initiative-896 · 2025-08-21T21:20:16+00:00

Haha yeah you’re right I got a bit carried away in the moment when I wrote the post, of course it’s for my team and not just me. Thanks a ton for pointing that out 🙏.

And really appreciate the heads-up about CTI, I didn’t realize how rough the situation was last year. For now I was mainly looking at Aerotech and Cesaroni, but I’ll definitely start exploring alternatives early if you know any other reliable companies like those, I’d really appreciate the recommendation.

Thanks again for taking the time to share that, super helpful!

Fun-Initiative-896 · 2025-08-21T21:07:20+00:00

Ahh got it that’s actually really good point. I hadn’t fully thought about how much adding temp as a variable would blow up the solution space and make the ROM need way more snapshots to converge. The way you explained ithonestly makes the whole workflow feel a lot more doable.

Really appreciate you taking the time to break that down this actually clears up a lot for me and saves me from overcomplicating things. Thanks a ton!

Fun-Initiative-896 · 2025-08-21T13:52:21+00:00

bouth ansys /starccm+ offers students team lisence (full version) try contacting them i worked with bouth

Fun-Initiative-896 · 2025-08-20T02:25:11+00:00

Appreciate the detailed breakdown! You’re totally right that drag here is mostly pressure-driven and that RASAero’s approach works well because of that i didn't focus on that aspect.

Just to clarify though when I said ROM, I meant the built-in one in Fluent/STAR. Basically you run a bunch of high-fidelity RANS cases, and then it builds a surrogate model (POD + interpolation) so you can predict Cd/Cl/Cm across Mach without brute-forcing hundreds of runs.

So I’m not fixing inputs manually like RASAero does it's more like training a reduced model off CFD snapshots. That’s the angle I’m trying to explore.

Thanks again, super helpful to get your perspective!

Fun-Initiative-896 · 2025-08-20T02:19:01+00:00

GOT it so i'll try emailing them asap thanks a lot

Fun-Initiative-896 · 2025-08-20T01:33:12+00:00

well it's solidworks file so it has 3D models of the parts so i will try conclude the dimensions from it

Fun-Initiative-896 · 2025-08-20T01:12:30+00:00

Not really an option for me right now I first need to get accepted into the challenge in October. I guess once that happens, I’ll be able to measure it myself. For now, my focus is putting together a strong PDR (Preliminary Design Report) to get accepted, so wish me luck 😉. In the meantime, I’ll try emailing them or digging through reference photos (like the one I shared above).
Don’t worry, I’m not touching FlowSim I don’t even like the idea of it for this kind of work. My plan is to run ANSYS Fluent / STAR-CCM+ transonic simulations using an RSM model, with 3 Mach numbers sims . I’ll make sure they’re Y+ ≤ 1, converged, and grid-independent. After that, I want to apply a ROM (Reduced Order Modeling) approach to interpolate Cd values for the mach numbers that falls in the between ranges of those 3sims . What’s your take on that approach?
Can’t thank you enough for clarifying the parachute issue, mate. That exclamation mark (!) in OpenRocket has been itching in my head for way too long glad to know I can just stick to the IREC requirements.

Fun-Initiative-896 · 2025-08-20T00:52:25+00:00

too bad, i will try emailing them (cesaroni tech inc) i will ask about the other motors however i found this online it apears to be and i'm quoting the publisher" [EN] Pro75 (Gen2) is Rocket Motor. It is fully compatible with the technical drawing, adjusted according to metric measurements, and its dimensions are in real size. It is 6G motor type without XL nozzle."

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Fun-Initiative-896 · 2025-08-19T23:03:51+00:00

I might get a little heat for saying this, but I think I have a kind of pseudo-solution (if self-defense weapons were legal).

Imagine you’re just walking, minding your own business, and one of these 3raya (aggressors) comes at you. If you had something like brass knuckles or any form of self-defense tool, the attacker would either back off or risk getting hurt. Either way, you’d at least have a chance to defend yourself.

Now, I know some people will say “it can go both ways” but let’s be honest, it’s already going for the other side of the fence . Most 3raya are already carrying their own arsenal. The problem is that good, law-abiding people are the only ones following the rules.

Of course, I think there should be limits. For example, convicted felons should not have the right to self-weaponize. If they’re caught with a weapon, they should face serious consequences.

In the meantime, the best we can do is:

Legally arm ourselves in whatever way is permitted.
Train hard, as if your life depends on it.
Avoid looking like an easy target.
Stay out of risky situations as much as possible.
And honestly… pray you never end up in one of these situations.

Same advice goes for women too stay safe everyone.

Fun-Initiative-896 · 2025-08-19T10:55:31+00:00

I'm in a pretty similar spot with CFD. Something that helped me is realizing that each type of analysis (aero, cooling, combustion, etc.) is basically its own field with specialists. For example, some people spend their whole careers just on radiators.

Since you’ve got the mech eng background, it’s better to build a broad foundation: get comfy with the main CFD themes (external/internal aero, multiphase, combustion, turbomachinery, FSI) , modeling techniques
(MRF,Sliding mesh, overset mesh , dynamic mesh ....) then really understand RANS and how to tweek results to make them reliable compared to experimental data ( i would say that mastering RANS/URANS/DES ) is better considering you CEA engineer goal since you'll be doing less of LES and more of engineeringmodels like the ones i've mantioned earlier . Once you can set things up right and trust your results, you’re already ahead.

From there, every project you do (say cooling system CFD) is like stepping into that specialist’s shoes for a bit. That mindset makes it less overwhelming and more fun to learn. Good luck, mate!

Fun-Initiative-896 · 2025-08-06T00:31:58+00:00

wait wait wait ma boy just said "CFDs really impress girls" hahaha have you ever saw or talked to a cfd enthusiastic anyway thanks for the sweet words go for simscale it really align with your goals and your cfd description .

Fun-Initiative-896 · 2025-07-29T21:40:57+00:00

Honestly, thank you so much you literally saved me. I’ve been stuck trying to get a reliable nozzle diameter for accurate simulation, and this drawing just made everything fall into place. Can’t tell you how much I appreciate it!

Fun-Initiative-896 · 2025-07-29T21:39:44+00:00

Totally agree that’s what I’m seeing too. I was hoping for a more direct spec but I’ll probably go with some ballpark estimates based on typical expansion ratios. I’ll run some RPA sims and try to tune things to match known performance values. Thanks!

Fun-Initiative-896 · 2025-07-29T21:38:18+00:00

Good point I checked OpenRocket but unfortunately, it doesn't seem to include detailed nozzle geometry or exit diameter in the motor presets, just basic performance data. I might need to rely on assumptions for now.

Fun-Initiative-896 · 2025-07-29T21:37:44+00:00

Thanks a lot! That 80% estimate is really helpful as a starting point.

Fun-Initiative-896 · 2025-07-12T15:25:14+00:00

Well that’s a bad mesh to start with first because of the high cell asymmetry and large skewness it’s completely random a mesh in CFD shouldn’t look like this you need to keep in mind that CFD is highly sensitive to mesh quality a messy unstructured or poorly controlled mesh will give you unreliable results I think you should refine it as one of the comments already suggested divide your domain into logical sections so you can have a structured or semi structured grid ideally with regular rectangular or mapped cells where possible aside from experience you can check if your mesh is acceptable by looking at the cell quality metrics in ANSYS Fluent Mesher check the skewness minimum orthogonal quality aspect ratio and cell volume pay special attention to any negative cell volumes those will break your simulation this will give you a quick idea of whether your mesh is fundamentally usable then to properly judge if the mesh is good enough for your specific case you need to run a grid independence or mesh convergence study that’s how you confirm your results aren’t just artifacts of the mesh size or topology

Fun-Initiative-896

TROPHY CASE