FLUENT 6.3 CFD software

[coreym]

Does anybody have experience using FLUENT to model hull design? Is it possible to learn such a program in a matter of a few months?

[marshmat]

I've used Fluent for a while, mostly for designing solarcars. It is fairly easy to get started, given its complexity and power, but coaxing useful and valid results out of it takes time, experience and a good eye for meshing.
It is absolutely essential when starting with Fluent to learn from someone who is experienced with the code and understands it well. Often this means taking lots of courses. Attempting to learn it on your own will simply not happen in a few months; there are far too many nuances and potential problems that you simply wouldn't catch without help at first.

[dimitarp]

I use Fluent too

[SOYUTA]

I wonder if it is possible to see hydrodinamic and aerodynamic problems of a hull in this program. I mean can this program supersede conventional test methods like model testing in pool or air tunnels?

[marshmat]

Just to clarify here:
FLUENT is a computational fluid dynamics program. It is designed to take a 2D or 3D CAD model, and simulate the fluid flow over/through that model. It does this by iteratively solving a set of partial differential equations, which are known to accurately represent fluid flow properties, over each of several thousand (or million, in some cases) simple 3D grid cells throughout the open space of the model. When the iterative solution has converged, you are left with a set of numbers representing the fluid's velocity, pressure, temperature, etc. at each of those grid cells.
If you set up the calculation correctly, the results can yield considerable insight into the actual behaviour of the fluid at any given point near the model. This is a substantial advantage over wind-tunnel or tank testing, where precise details of the flow are difficult or impossible to identify.
The drawback is that to get good, useful results and accurate force/pressure numbers, you need a lot of experience with the software and a good eye for flow patterns. It is quite easy to screw up in the early stages of preprocessing the CAD model (a very labour-intensive process) and end up with a mesh that yields inaccurate results. It's just as easy to specify an incorrect relaxation factor somewhere, and send the results oscillating off to infinity after ten hours of computation. So in short, CFD codes can (almost) replace model testing, and are preferable in many respects, but require considerable skill and experience in order to be useful.

[SOYUTA]

Hello Marsmat
I heard much good things about this software but couldn't be sure. But now I am sure. So now I really want to learn to use this softwares. But I don't know how to do it What kind of substructure should I have? And how can I use it most efficiently? For designing new boats, most efficient boats it is a preferential ability I think.

[PI Design]

Fluent is one of the best CFD packages around (but not affordable to most ameteurs?). It is fairly easy to get pretty pictures but, as others have said, getting accurate results requires a lot of experience and understanding. Tank tests are still considered more accurate and are essential for validation purposes.

[cfdking]

Have you tried ANSYS_CFX rahter than Fluent. Similar results but much easier to setup and understand

[PI Design]

Don't ANSYS own Fluent as well now? Other than the fact that CFX is easier to pre-process, what is the difference? The ANSYS website uses exactly the same words to describe both. Did they just but Fluent to kill it off?

[cfdking]

Yes ANSYS do own Fluent, but as I understand it there are 2 niche areas for the development of the software. CFX is being used by the americas cup teams, Alinghi, Shosloza and BMW oracle. I think Fluent is being developed for the automotive and aerospace environments