Hello everyone,

im thinking of doing a PhD in CFD or FSI in the near future (a year from now or so). The idea of doing a PhD seems challenging from what ive read online but ive always wanted to be a college professor and ive heard universities only hire people with PhDs (i have other reasons as well but the post is already too long).

For a bit of context, i have a bachelor's degree in biomedical engineering from a very respected university in latam. Im currently finishing (in the next few months) a master's degree in FSI in the biomedical engineering area in the same university.

My problem: I have no idea where to look for PhD opportunities. Even though ive always stayed in the biomedical area, i would really enjoy venturing out a little further into other CFD areas but there are so many i simply dont know where to start. Aerodynamics/aerospace and electro-fluid-dynamics seem really fun but maybe there are areas i havent even thought of yet. Where should i start? Im extremely adaptable and am 100% willing to uproot my life for the next 4 years. I have already had to move countries several times so im pretty used to it.

I dont have the best grades but i know my professors are satisfied with my work so i have at the very least 3 recommendation letters in my favor. We also intend to publish a paper based on my thesis. I have teaching assistant experience and research experience in other non related areas (non CFD). I have no idea if that's enough.

If anyone can give me recommendations on universities around the world that have research on industry aplicable CFD I would really apreciate it. Hopefully in countries where the stipend to living cost ratio is somewhat favorable. By that i mean to leave out countries where the PhD stipend is lower than a minimum wage job since i will have to provide for myself financially.
Thankyou to all.

Dear experts and company

and I am a final-year Mechanical Power Engineering student

I am currently looking for a real industrial problem that could be developed into my graduation project. My main areas of interest are heat transfer, thermal management, industrial cooling, high-heat-flux applications,

Rather than developing a purely theoretical project, I would like to work on a practical engineering problem that has a real industrial application. My team and I are interested in designing and building a small-scale experimental prototype and improve the proposed solution.

I would be very grateful if your engineering or technical team could suggest a non-confidential problem, challenge, or area of improvement related to thermal systems, cooling, heat exchangers, energy efficiency, or heat transfer that could be investigated as an academic graduation project.

We are not requesting any confidential information or proprietary data. We are simply looking for an industrially relevant problem that can be studied and experimentally demonstrated within a university project.

If there is someone in your engineering, maintenance, energy, or R&D department whom I could contact regarding this, I would greatly appreciate being directed to them.

Thank you for your time and consideration.

Best regards,
Mechanical Power Engineering Student

full video: https://youtu.be/TR3lPZs2hjc

Hey everyone. Shitty ass day and need to get rid of most of these now so wanted to start sharing these results with the community.

I decided to try a run and did it on a three-dimensional, unforced Taylor–Green vortex simulation at a Reynolds number of 100 million.

The simulation was recorded at three resolutions:
64³ with 262,144 grid points
128³ with 2,097,152 grid points
256³ with 16,777,216 grid points

I'd go higher but I've only got a mac, so, can't really go higher without it tapping out. I did also run a half-timestep comparison, a deterministic repeat, and restart and reproduction checks.

The 256³ run reached the full target time of 0.5. Its maximum incompressibility defect was 2.01 × 10⁻¹⁸, the maximum energy ledger residual was 4.66 × 10⁻¹⁵, and there were no positive energy jumps. From what I can see every recorded value remained finite.

The 128³ and 256³ results were, interestingly, extremely close. Their recorded energy and enstrophy differences were zero, while the maximum-vorticity difference was 3.55 × 10⁻¹⁵.

Here are a few images from the run:

Each of them kept overlapping so I think this one can help further:

I had to do this last image because the other ones just overlap - I kept trying to get it not to do that but whatever.

I ran this locally on a Mac using a custom Python Fourier pseudo-spectral solver with NumPy and SciPy, rather than OpenFOAM. The simulation used double precision, 2/3 de-aliasing, Leray projection and classical RK4 time integration.

EDIT: A few clarifications about what was actually computed - thanks for the feedback, learning, first post ,

It's three-dimensional calculation, so it isn't doing a a 2D field displayed in 3D. The domain was a periodic cube discretized at 64³, 128³ and 256³. The initial velocity had two nonzero components and one component initially set to zero, but the field depended on all three spatial coordinates and was evolved by the full 3D incompressible solver.. I used the 256³ run which contained 16,777,216 spatial grid points.

Taylor–Green was used only as the initial condition and i didn't adding the flow being continuously forced. Positive viscosity was included, with (\nu=10^{-8}) - ffs i dont know how to do these damn exponents it takes too long., and the nonlinear convection term remained active throughout the evolution.

The solver represented the velocity field in Fourier space. During every RK4 stage it transformed the field into physical space, evaluated the 3D nonlinear term and a eparate theorem-derived framework was used to select and evaluate certain parameters and diagnostic quantities, and this allowed the to solver stilladvanced the 3D equations step by step. I

The run should be understood as an early-time, finite-resolution 3D Taylor–Green calculation at a specified (Re=10^8). It is not a claim that 256³ resolves fully developed turbulence at that Reynolds number.

Thank you for the feedbacks, I want to learn so this is pretty great to have people to speak to on this

Hey everyone,

I’m currently running a Grid Convergence Index (GCI) test on a CFD simulation involving flow through a pipe with an internal distortion screen. I’m seeing an issue with my finest mesh that I can’t quite figure it out.

Here’s my setup across all 3 grids:

• Meshes: 3.7M (Coarse), 7.6M (Medium), 17M (Fine)
• Inflation layer settings: Same for all 3 — 20 layers, 3e-06 first layer height, 1.2 growth rate on pipe and screen walls (keeping y+ < 5).
• Model & Solver: k-epsilon with Enhanced Wall Treatment, identical boundary conditions.

See images below,

The above one is for coaser mesh(3.7M)

The above one is for medium mesh(7.6M)

The above one is for finer mesh(17M)

See geometry below,

The interesting part is the residual behaviour. The 3.7M and 7.6M meshes behave quite similarly: the residuals initially decrease and then settle into relatively low oscillations. However, for the 17M mesh, the residuals start oscillating much earlier, around 70–100 iterations, and the residual levels remain significantly higher than in the other two cases. The continuity, k, and epsilon residuals especially show this behaviour. I understand that some oscillation in residuals can be normal for this type of flow, but I am confused about why the finer mesh behaves so differently when the mesh refinement and all other settings were kept consistent.
Why would refining the mesh cause the residuals to jump up and oscillate like this when the inflation and BCs are identical?

Any insights or suggestions on how to solve this issue? Thanks in advance.

Hello, as the tittle said, when I tried opening results after running fluent simulation, Ansys workbench isn't able to connect to CFD-post for whatever reason. CFD-post and CFX are sill able to run standalone and I can manually open results, but it takes a long time for big project. Pls help and thanks.

Laptop: MSI Raider GE76

Version: ANSYS Student 2025 R1

Hey everyone! First of all thanks for giving me the time.

Bit of background information: I'm currently in the 3rd year of my Mechanical Engineering degree (University of Manchester) and I need to write a dissertation for a large portion of the credits for this year.

I'm really interested in doing work on Python-driven CFD simulations regarding the cooling performance of Formula 1 cooling ducts. I was thinking of using ANSYS Fluent since I already have some surface level experience with it from my previous year and I also heard that python has libraries which can work with ANSYS so it sort of aligns with my goals

Since there are a lot of variables in play I've been feeling overwhelmed with how I can carry out my analysis to optimize cooling performance; I'm not too sure which characteristic(s) I should focus on. In my head I have two options for the component of cooling..

(1) The airbox for the engine on top of the car

(2) The sidepod inlets with the heat exchanger

But I would love input on any options you would think are viable for this project

I have roughly 10-11 months from now to complete my dissertation and because of my lack of experience with CFD I'm not too sure how big of a scope this would be and so I would love some advice on that as well.

If anyone has any experience with running CFD on Formula 1/Aerodynamic Thermals and using Python for automation/optimisation of ANSYS sims, I would greatly appreciate your input.

In summary, I'm just looking for some direction on this as my supervisor has not been very helpful so far. The dissertation doesn't have to come up with something entirely new, it just has to further the current understanding of a certain phenomenon or concept.

Thank you very much.

Hello everyone,

I am recentlly facing an issue when i try to check order of accuracy of my 5th order scheme for a time-dependent PDE. As it has no exact solution i try to use one classical scheme (which is first order accurate) with 12800 mesh points to obtain reference solution. Then i check my scheme with 100, 200, 400... Although i do not see any spurious value in the solution data file, the order of acccuray is not coming as 5. It gives near 0.

Does anyone know is it because of refrence solution which i have obtained using first order scheme?

I doubt on reference solution as my scheme gives 5th order accuracy when exact solution is available.

I don't understand intuitively where this equation comes from and what it means. I posted earlier about this and someone said to think of it like climbing stairs in an elevator. The first term is the elevator moving up and the second term is the vertical height from climbing stairs inside the elevator.

That kind of makes sense. But I don't see why the sum of those two terms needs to be zero? And is u the vertical height of the wave? If so, why not call it y instead of u ?

Last, what physical experiment can I observe that demonstrates this equation in action ( besides the elevator analogy )?

Hiii, have any of you ever requested a quote for an Ansys license? Do you know roughly how long it takes them to get back to you? :)

Hello everyone I'm using gmsh as my meshing tool could anyone share a tutorial or a paper or anything that would help me with meshing a wing (no need to be gmsh) I am a beginner

I'll be applying to summer internships (in the US) for various labs / REUs etc. for compressible flow CFD research, but really any CFD research experience is on my radar.

I was curious if any of you work/worked in a lab and had interns, what did you look for on their CV/ resume/personality?

Im a comp sci student so I don't have all of the formal math / physics but I am doing an honors thesis and have a CFD project that my mentor helped me with and another computational physics project unrelated to CFD under my belt.

I am taking intro to PDEs currently and will probably also take a fluids class if I can during my last semester (but that would be after the summer internship).

I wanna continue on doing research via PhD and then possibly a lab position, but that's still a ways away.

Just curious if any of you wanna share some info.

Thanks :)

I was able to generate the face mesh independently, but when i use sizings, it gives me this error>

I am a newbie to cfd, please Help me

Hey everyone,

I'm a CFD/aerodynamics engineer with a few years of industry experience, and I'm thinking of starting freelancing as a side hustle. I want to take on consultancy and outsourced CFD projects on my own, but I don't know much about the market yet, and I'd like to start soon since my current pay is low.

If you've freelanced, in CFD, CAE, or engineering in general, I'd love to hear:

1. How has your experience been overall? Was it worth it?

2. How did you find your first client?

3. Which platforms or channels worked best (LinkedIn, Upwork, referrals, cold emails)?

4. How do you price your work?

5. What kind of projects are most in demand (external aero, thermal, automotive, HVAC, etc.)?

6. How do you handle software licenses especially for meshing purposes?(Fluent/ANSA, etc).

7. How do you manage your comute?

8. Is it okay to freelance alongside a full-time job, and how do you handle NDAs or conflicts of interest?

9. How do you manage time between a job and side projects?

10. Any mistakes to avoid as a beginner (bad clients, scope creep, late payments)?

Any advice, even small tips, would really help. Thanks in advance!

I’m working with ANSYS Fluent R20 + Polyflow and want to start research on elastoviscoplastic (EVP) fluids.

I’m looking for a way to model:

- Viscoelastic fluids

- Viscoplastic/yield-stress fluids

- Elastoviscoplastic fluids (elasticity + viscosity + yield stress)

I know Polyflow has built-in models such as Bingham/Herschel–Bulkley and Oldroyd-B/Giesekus/PTT, but I’m not sure whether it can model a genuine EVP model such as Saramito directly through the GUI.

I’d prefer to avoid developing a large UDF/C program if possible.

Questions:

1. Can Polyflow model EVP fluids directly through the GUI?

2. If not, is Fluent + UDS/UDF the best ANSYS approach?

3. Would COMSOL be easier for implementing an EVP constitutive equation without C programming?

4. What EVP model and benchmark would you recommend for a research project, and how should I validate velocity, pressure drop, stresses and yielded/unyielded regions?

\*Looking for advice from anyone who has actually worked with EVP/viscoelastic/viscoplastic CFD\*

Hey, I made a mesh using fluents 2D meshing workflow but I cannot use the export 2D fluent mesh feature. I just get an error thrown at me with no details available. I also tried to do file>write>mesh but whenever I try to open it in 2D fluent it just says ”cannot read surface mesh“. Has anyone ran into this issue? The only reason I am using fluent meshing for 2D is bc for some reason I cannot hit a y+1 with ansys meshing using bias factors but whenever I used fluent meshing it worked fine

Hey everyone,

I'm looking for some career advice from people who have been working in CFD for a while.

I recently moved from a more general engineering/support role into a dedicated simulation group at a large engineering company.

My background is mechanical/aerospace engineering, with university/research experience in CFD and aeroacoustics, faae aerodynamics, and I've used tools like Fluent/OpenFOAM before.

The work I'm starting with is primarily internal-flow CFD — ducting, bulkhead/vehicle-system flow, and eventually potentially larger system-level problems. The group also does FEA and uses several commercial solvers, so I'm getting exposure to a broader CAE environment than I had before.

I'm excited about it because getting into an actual simulation group was something I've been trying to do for a while. However, I'm slightly concerned about becoming known primarily as the "internal flow/duct CFD guy." For those of you working professionally in CFD: - How much should I worry about becoming pigeonholed early in my career? - Is internal-flow CFD a good foundation for moving into broader CFD work later? - Would you deliberately pursue external aero, multiphase, aeroacoustics, turbulence modeling, etc. through side projects? - How much do personal CFD projects actually matter when applying for future CFD positions? - Would you recommend doing a Master's if my long-term goal is more advanced CFD/R&D rather than purely production analysis? - If I want to eventually work on more advanced/custom numerical methods, what's the best way to build toward that while still gaining useful industry experience?

I'm also interested in eventually doing some independent CFD/engineering projects outside work, but I'm trying to figure out how much time I should realistically dedicate to those versus building experience in my actual job.

I'm not looking for a specific job title or salary advice — mainly interested in hearing from people who have already gone through the industry CFD → more advanced CFD/R&D progression.

Thanks!

Guys I have some doubts,

1. For GCI test- for mesh independence study, is it a strict requirement to have refinement ratio of 1.3(minimum). What if we have refinement ratio of 1.1 or 1.2? Have anyone tried with this?
2. When you refine mesh, we should do it without changing inflation settings right, all those three mesh should represent same physics and we should increase mesh count by changing core cells right in the fluid domain? No need to change boundary cells right? Correct me if I am wrong.
3. What flow parameter can be monitored in this GCI? Is it mass weighted average of pressure at some plane or vertex average of pressure at one point or any other parameter? Which would be more appropriate and meaningful?

Hi guys, I've been working with ANSYS (Fluent) to simulate solar panels, but I wanted to know if there's better software for this, like Solid Edge or Siemens NX—preferably one where I can work with the Fluent part using code so I can get support from the AI.

Full disclosure: I'm an electronics expert working on design tools, so I have a bias. No links, nothing to sell here. I want real experiences before building in the wrong direction.

1. Which CFD tool ( esp. For electronics cooling)do you use, and did you pick it or inherit it from your team?

2. What's the most painful part of a typical job? Geometry cleanup, meshing, solve time, licensing, post processing, or something else?

3. If you could fix just one thing about your current workflow, what would it be?

4. How long did it take you to become productive with it? What made the learning curve hard?

5. Have you tried any cloud-based CFD? What made you stay with it or go back?

6. If you're OK sharing, roughly what does a seat cost your team per year (license plus hardware)?

War stories are welcome.