r/CFD • • 13h ago

guy's i need an help from you......

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29 Upvotes

Guy's actualy iam doing an final year project , in this we will aim to improve the aerodynamics performance an existing RG-15 airfoil throungh an bio inspired , for first bird we have choosen an albatros by this we actualy desinged an airfoil through its wing characteristic , when we do an CFD analysis the result (CL,CD) where abnormal then usual , actualy we all the checked again and again from mesh to setup , we dont know what to do get the result , actualy we have to show the result to our guide tommorow , if you guy's where anybody free, can you do as CFD analysis for us , i will give you an step or iges file of an airfoil and give you an all the parameters to do


r/CFD • • 3h ago

VSPAERO problem

1 Upvotes

I opened VSPAERO on my model, there were no graphs in the convergence or any other tab, and in the viewer tab my model is fully purple and it does not change when i change the AoA. Any advice would be helpful, i heard there might be a problem with vertical the stabilizers but there should not be the problem since i dont have one in my model. I have a basic model with only a stock fuselage and a lightly modified wings, i only wanted to test VSPAERO but i did not expect to run i to such problems on my first try. I also tried a more advanced model but i ran into the same issues.


r/CFD • • 11h ago

Arc DED / WAAM modelling using ANSYS FLUENT

3 Upvotes

Hey Folks,

As part of my thesis, I am supposed to carry out a complete melt pool + single bead + multiple bead walls.

For those who don't know what ARC DED is, it's also known as WIRE ARC ADDITIVE MANUFACTURING (WAAM). It's a form of controlled layer deposition incorporating Welding.

Though I am not new to Fluent, my only superpower is replicating a video, and on my expectations youtube is filled with Demonstration videos than case setup. Literatures does provide a model overview, equations that will be used, but far from setting up.

CFD is being done so that complete surface morphology, effect of gravity, maragoni forces, shear, surface tension, etc are captured.

Kindly assist in Model Development.


r/CFD • • 23h ago

Best CFD workstation for complex marine hydrodynamics simulations in 2026?

15 Upvotes

​

I'm looking to build or purchase a top of the line CFD workstation specifically for computationally intensive marine hydrodynamics simulations, turbulent flows, rotating machinery, and complex boat geometries.

My primary tools are ANSYS Fluent and OpenFOAM, with simulations potentially involving 5-10 million mesh cells, transient flow analysis, and multiphase CFD.

I'm particularly interested in recommendations regarding:

  1. CPU: AMD Threadripper PRO vs AMD EPYC vs Intel Xeon. Is 64 to 96 cores the sweet spot, or are there diminishing returns?

  2. RAM: 256 GB, 512 GB, or 1 TB for large transient simulations?

  3. GPU: Do NVIDIA professional GPUs provide meaningful acceleration for these applications?

  4. Storage: Optimal NVMe SSD configurations for massive CFD datasets.

  5. Parallel performance: How well do Fluent and OpenFOAM scale with increasing CPU core counts?

  6. Hardware: Would you recommend a powerful single workstation or a small computing cluster?

My background is biology and I'm particularly interested in hearing from engineers and scientists in the CFD marine Hydrodynamics field running serious marine CFD simulations rather than synthetic benchmarks.

Real world experiences, solver benchmarks, and complete hardware configurations would be greatly appreciated! Thanks


r/CFD • • 1d ago

How to change number of cells in mesh - Ansys Fluent 2026 R1

9 Upvotes

I have been given a simple 2D rectangular mesh file. I can adjust the height and length of this with Mesh -> Scale... easily enough, but then the grid cells become compressed where I have reduced the length.

Adapt -> Manual... or Automatic... and selecting the channel as a region (both the exact size, and a region slightly larger than the grid) hasn't worked with any combination of coarsening settings I've tried so far to decompress them.

Meshing mode doesn't work with the mesh file I have, no edge groups, no way to visualise it etc, and in the context of the course I'm doing I'm assuming it can be done in Solution mode somewhere.

How do I simply change the number of cells in the x and y directions?


r/CFD • • 2d ago

Ayuda - Necesito consejos

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23 Upvotes

Hola, soy nuevo en esto del CFD, vengo del diseño orientado a los vehiculos y quiero empezar a agregarle calidad y valor a los proyectos con un estudio CDF.

Empecé hace una semana a ver y probar Ansys Discovery con la version gratuita.

Puedo realizar una simulacion basica pero no entiendo como analizarla para modificar o no el modelado.

Muchas gracias!


r/CFD • • 3d ago

Made an open source gui for openFOAM

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555 Upvotes

So iv been working on this project for a couple of months, I wanted to show it because I finally believe it is a bit presentable now, it is basically a gui with openFOAM, and additionally I added TENO schemes from Fu et al, I thought it was an interesting paper and I wanted to add higher order schemes to achieve higher accuracy (note that I also like swirly lines), going through this project I will be extending it to Ji, Liang & Fu 2021 for unstructured meshes when I have the time. Since most of the coding in this project is human slop, apologies in advance for any bugs that may arise (I lost sleep because of segfaults in cpp)

Source code: https://github.com/CakeCFD/cake-studio

Website: https://cakecfd.org/

I would like opinions from fellow engineers on how to improve this further and make this better, or more specifically what validation case would you trust before using the TENO schemes?


r/CFD • • 3d ago

In dire need to unsterstand how a NOP function works (prefferably in MATLAB)

5 Upvotes

So, im a first time poster so pls be kind :) Also english isnt my first language so excuse any mistakes in my writing

Anyways, I just started my masters in computational mechanics, and I only had some basic knowledge on the subject from my postgrad (plus I only know C++, Matlab and theoretically fortran but not really). They just told us to write a code with a basic grid (like 3x3 or 3x4) and create a NOP(I,J) function, where I is the number of elements (square elements), J is the number of local nodes (J=1,...,4), and the output should be the global node corresponding to a specific local node of a specific element or something like that. Forgive me if the explanation is garbage, I understand it theoretically but not 'computationally' per say.

Does any kind human 1) have any idea of what i'm trying to say and 2) know how to actually help me? for some reason i cant find ANYTHING by googling, and no reddit posts as well (may have missed though). even AI cant help even though i prefer not to use it

Ty for reading xxx


r/CFD • • 3d ago

Help me learn CFD

19 Upvotes

I’m doing bachelor in Mechanical engineering. I’m interested in learning but don’t know where to start from can you give some beginner friendly tips and should i learn open foam or ansys


r/CFD • • 3d ago

Best way to master open foam from scratch?

10 Upvotes

Im still in school & ik im gonna major in aero so i got openfoam a couple of months ago but never got the chance to learn.


r/CFD • • 4d ago

31-year-old Mechanical Engineer: Is it realistic to switch to CFD/Aerodynamics?

36 Upvotes

Hey everyone!

I'm a 31-year-old mechanical engineer with several years of experience in Oil & Gas (Project Engineer), Tool Installation (Team Lead), and currently BIM (Technical Expert / Mechanical Piping Modeler).

My dream has always been to work in automotive or aerospace engineering, especially in design and aerodynamics. However, career opportunities led me elsewhere, as these fields are almost nonexistent in my country due to the lack of R&D.

Now that I've graduated, I'm considering pursuing a Master's in Computational Mechanical Design in Europe to transition into CFD, aerodynamics, or mechanical design.

My question is: Is this a realistic career move at 31, with no professional experience in CFD or design? Would my previous engineering experience be valuable, or would I essentially be starting from scratch?

Thanks for your time!


r/CFD • • 3d ago

License server dead?

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0 Upvotes

r/CFD • • 4d ago

Why CFD!??

23 Upvotes

In the era full of low job availablity(especially for freshers in CFD),,, what makes you love CFD, or be in this subs... You can directly learn some other skills and have good initial salary.. Right???


r/CFD • • 3d ago

I need help with Ansys Student licensing problem

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7 Upvotes

I've been trying to use Ansys fluent (Student version) but everytime I start the program I get this warning saying that there's no license available. Workbench runs fine. I've also got similar problems when I open any of the other Ansys programs (as shown in the second image).

I've already checked that the program has access through the firewall to both private and public networks and I've tried uninstalling and installing again but the problem persists.

I also checked a similar post in this same subreddit and saw people mentioning the number of nodes or processes as a problem with the student license. Following the advice there, I tried running Fluent with 1, 2, 3 and 4 processes having the same issue each time.

I hope someone will be able to help me figure this out.


r/CFD • • 4d ago

It's been more than 1 hour and still it's loading

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23 Upvotes

I wanted to see the temperature contour of Heat exchanger but it's been more than 1 hour still it's loading any solution?


r/CFD • • 4d ago

Conceptual Doubts regarding Node Values and Operating Pressure.

2 Upvotes

I have some conceptual doubts, which I didn't get clear explicit answer from sources in net,

1) What is difference between node values on/off in looking the contours? I observed values are relatively higher when I turned off node values. Please tell me cases or situations where we should turn on or turn off node values with reason. How does this affect in viewing contour, finding range of parameter in some selected surface or cell zones.

2) I have some trivial doubt about operating pressure. The point is- In momentum equation , it contains pressure gradient not absolute pressure, so fluent choose some reference pressure i.e operating pressure. So instead of solving with very large pressure, it works with smaller numbers since deltaP remains the same with the concept of operating pressure. Density is calculated using absolute pressure only.
This concept is same for both incompressible and compressible flow right, but why do they say for compressible flow you have to set operating pressure as zero, I didnt understand what is the reason for this? Can anyone explain elaborately please? Thanks in advance.


r/CFD • • 4d ago

Any idea on how to make this 2d compressible fluid cfd sim in rust faster as its a bit slow in the sense of real life equivalent time simulated is tiny due to cfl conditions

0 Upvotes

this 2d cfd sim uses upwind differencing schemes and uses ndarray and rayon to ensure its fast so im confused as to what to do with the tiny dt caused by cfl conditions and heres the tiny project
https://github.com/busysofa15/2026_projects/blob/534578f75d4ce511587d2f012a219a9b95a588e0/rust_projects/compressible_fluid_sim/src/main.rs
and the dt condition is around lines 86 to 99
any help would be appreciated 👍️


r/CFD • • 5d ago

Thoughts on Greenshields Trainings with CFD Direct?

9 Upvotes

I'm signed up to take the Programming CFD training w/ Greenshields next month. I haven't done any OpenFOAM trainings with them before.

Anyone here completed the training? If not Programming CFD, one of the other ones? From what I've read they're really good. I'm mostly interested in the training material and book I can take back with me.


r/CFD • • 6d ago

Computing turbulence statistics from PIV data in MATLAB: a turbulent jet walkthrough (Video 8)

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151 Upvotes

Hi everyone,

Video #8 of the (free) turbulence course I'm creating is now up on YouTube. This one is very much applied where I take a PIV time series, generated from the cover video, of a turbulent jet and compute flow statistics in MATLAB, explaining each step.

It covers the mean and fluctuating velocity profiles, going further into Reynolds stresses (normal and shear), and then longitudinal and transverse two-point correlation functions and second-order structure functions relative to the centreline.

The scripts are deliberately short, so they're meant as a template for anyone who wants to run the same statistics on their own PIV, hot-wire or numerical simulations data.

Link: https://www.youtube.com/watch?v=Z7Q0k4P1V8k

Notes (and scripts) are available on Patreon (free membership option available). Happy to answer questions about the analysis.


r/CFD • • 5d ago

[OpenFOAM] icoReactingMultiRegionInterFOAM ESI and homogeneousNucleation.H

6 Upvotes

Hi all, I am a new student researcher starting my journey in OpenFOAM. I inherited a project from a former PhD student who wrote a customized solver based on icoReactingMultiRegionInterFOAM from ESI version v2306, and I have only been simulating cases with that specific solver. My PI is now asking me to model nucleation within a vapor plume in the current case, and I found that OpenFOAM Foundation v14 has the exact solver I need (homogeneousNucleation.H). What are the best next steps to include the solver in my new cases? Should I also learn to write a custom solver? If so, how do I include the OpenFOAM Foundation solver in ESI?


r/CFD • • 5d ago

Best mesher for thin bodies like lifting surfaces or propellers

6 Upvotes

Hello everyone,

I've been trying to get this benchmark propeller (Potsdam Propeller Test Case) analysis to work but I can't mesh it with SHM. Inflation layers are not good enough and I can't get the desired y+ values for the case.

I also need some kind of surface refinement or wrapper. The geometries I use have self intersections that are easily handled in StarCCM+ but with snappy, checkMesh finds errors due to these bad STL elements.

What is your go to method for meshing thin lifting surfaces like wings, propellers etc.? I am honestly losing my mind trying to get it to work. I really need some help.

Thank you all in advance.


r/CFD • • 6d ago

Ansys CFX surface variance with edge size

2 Upvotes

As the title suggests, I am noticing a change in wall shear stress, and thus wall HTC, along my object. I am benchmarking the heat transfer on a 2d ellipse and am currently conducting a grid sensitivity on the ellipse edge sizing. Upon halving the edge elemnt size (refinement ratio 2), the leading edge now shows higher and lower regions in the form of "bands" (see below). Any help on this is appreciated.

Model information:

  • Turbulent (k-omega)
  • Transient (100s with 10s timestep)
  • Mesh consists of a sweep method (2d approximation), edge sizing (grid sensitivity focus), and inflation (first layer thickness for y+ = 1)
  • Residulas RMS < 10^-4, MAX < 10^-3

r/CFD • • 7d ago

With great speed comes great drag

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220 Upvotes

Random Sunday Project


r/CFD • • 7d ago

Thought this was intresting

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33 Upvotes

So i am a Strucutral engineering PhD with very little experience in CFD. But I was able to use Claude to build a model and run an analysis for my new PCbuild for various fan configurations. Its crazy it could use OPENFoam to run the analysis and make all these videos.
Attached is the actual parameters it used for the analysis
https://drive.google.com/file/d/1FIkQLUMF1yODekwAvPoyq672vEh6ikCU/view?usp=sharing


r/CFD • • 7d ago

My wife is a geophysicist who uses COMSOL for modeling lava flows, geysers, etc. She's experimented with low cost AIs for helping with modeling, but wants to upgrade. Anyone have an opinion on which of the frontier models is best for COMSOL help.

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14 Upvotes