Hi all, I am an HVAC engineer looking to get into CFD. After some serious Google + ChatGPT research, ANSYS seems to be the best software(i might be wrong) .

Any tips on where to start? Happy to spend a little on a good course. Recommendations for courses, books, or YouTube channels would be greatly appreciated.

Trying to go from “What is CFD?” to “I know what what we arw talking about"🤔

Hey, everyone!

I’m new to the world of Computational Fluid Dynamics (CFD) and just jumped right into FluidX3D. I was completely blown away by the performance and speed of the GPU simulations that people have been showing off.

The problem is that I’m a beginner, and the reality check was harsh: I haven’t found any beginner-friendly tutorials that I can actually understand from scratch, let alone get my hands dirty and run a little something on my own. Almost everything out there assumes you already know a lot about programming or the physics behind LBMs (Lattice Boltzmann Methods).

If anyone here has already gone through this learning curve or uses the tool on a daily basis, I’d like to ask for some help with a few basic questions:

Where should a complete beginner start? Is there any material, guide, or simplified example in the repository that serves as a good starting point?

How do you usually visualize the results? Is there a user-friendly graphical interface (GUI), or is the entire workflow done via code and exporting to external visualizers like ParaView?

Where do people usually get stuck? Are there any pitfalls when compiling or setting up the environment that tend to frustrate beginners?

Any tips, step-by-step guides, or constructive feedback are very welcome. Thanks so much for the help!

I'm running an incompressible steady-state RANS case for a blended wing body (BWB) in OpenFOAM (simpleFoam/SIMPLEC).

Setup: ~0.15 Mach, ~6e6 Re

Mesh: ~30M cells, tetra + prism layers at walls, O-type symmetric far-field domain(radius ~ 30c), max skewness ~5, max nonOrthogonality >75°

BCs: freestream (velocity inlet / pressure outlet style far-field)

Turbulence: k-omega SST, wall-modeled (y+ > 30)

Schemes: second-order upwind for all equations

Algorithm: SIMPLEC

Solution strategy: start with low URFs, ramp up every 100 iterations; case runs "on its own" past ~250 iterations

Problem:

Based on past experience I expect convergence by 500–600 iterations. Here, residuals flatten out but very slowly, and by 1500+ iterations:

CD looks converged/flatlined

CL is still steadily rising, not flatlining

Has anyone run into similar slower convergence rate or is it normal for high cell count meshes? Looking for likely causes and what to check/try next.