Oid fashion look of FLUENT
 

Hi all,

I work with FLUENT and ANSYS-CFX. From a numerical point of view, models and applications both are fine. However, the GUI of FLUENT is very old fashioned. Will there ever be an update? I think it still looks like an ancient Unix application.

FLUENT is the marketleader, so their marketing must be very good. But there will be a day that new customers do not accept the old look anymore. ANSYS-CFX looks modern, is fully integrated in an CAD environment and works more intuitively.

Astrid

Re: Oid fashion look of FLUENT
 

Hi Astrid, I think fluent is a technical stuff and not a playstation.

regards, bharat

Re: Oid fashion look of FLUENT
 

Playstation or not, a agree with Astrid that fluents appearence is not very appealing. If you add the fact that some important menues are scatterd all over the place or hard to reach (especially the ones for postprocessing) you will agree that there is alot room for improvement. Good news is that fluent rewrites the cortex in python and hopefully the new one will be more user friendly.

RoM

Re: Oid fashion look of FLUENT
 

i infact like this gui very much for its simplicity. More than gui its important for me that the solver shall give me converged results. and fluent is very stable compared to those fancy gui solvers. To give you an example, there is lot of talk about starCCM+ gui, that how good it is, but the thing is i have some very small meshes, on which i was doign some experiments and yes i could not make fluent to diverge on these meshes, where as starCCM+ i could not get converged solution. I would prefer a solver that is stable to a solver that can diverge but has fantastic gui.

Re: Oid fashion look of FLUENT
 

OK. I do not have experience with StarCCM+. I know ANSYS CFX which is at least as stable as FLUENT. What I actually meant is that large organizations with a lot of documents use filemanagement systems (e.g. PDM software). There will be a day that CFD-applications have to be integrated into those systems. In that respect, I think ANSYS-CFX is much better prepared than FLUENT. Therefore, I was wondering what FLUENT is planning for the future.

Astrid

Re: Oid fashion look of FLUENT
 

I'd like to express my point of view about this topic. Fist of all I'm a Fluent user. I never used personally CFX but I saw it working.I agree that CFX GUI is fantastic, with its CAD integrated in the solver. Playstation ot not, stability convergence ot not, who would not like to have in FLuent the same CFX GUI?!?This is a thing I think Fluent could improve since to be honest Fluent GUI is old. But what I think is the main lack of Fluent is the capability to run a coupled simulation. Ansys has an environment capable of coupling CFX, Icem and Ansys structural solver, and this is great. Try to do the same with Fluent...it's a really hard job.This is my point of view, so I'd like to have a new GUI, but anyway I think the before this Fluent has many other stuff to improve. Luca

Re: Oid fashion look of FLUENT
 

actually i also wish to see them improving the CAD-Solver integration, which currently sucks. If the situation is too complecated gambit is most likely to get stuck. About the GUI the main thing is the current gui does not have advanced things on it, it is one way good since a normal user does not use lot of advanced features and the gui does not confuse user. But when we have to use advanced features we do not have documentation properly telling us where is feature is. Most of the users do not know even 20 percent of features of Fluent. The best thing that fluent can do is to improve the documentation.

About coupled solver, the coupled solver in CFX and Fluent are different, but fluent has one big advantage that CFX does not offer. That is with coupled solver full multigrid. With this feature the solution converges very fast, CFX currently can not match this.

Re: Oid fashion look of FLUENT
 

Yes zxaar, when I was talking about "there's a lot of stuff to improve before" I was talking about the documentation which is really poor but I think this is done purposely. I'm writing a lot of UDF and scheme macros, but it's an hard. I'm sorry when I talked about COUPLED I didn't mean the way fluid-equations are solved but INTEGRATED capability of analysis (AEROELASTICY in my case). Luca

Re: Oid fashion look of FLUENT
 

i also think docs is purposely bad, i mean fluent is such a big company if they wish they can improve it anytime. But they do not wish to. its sad.

Re: Oid fashion look of FLUENT
 

BTW zxaar,

CFX solver is a coupled AMG solver.

Fluent's coupled solver is Rampant's solver which as a compressible flow solver is density-based.

This means it will not well (i.e. the reason it diverges) when drho/dn is 0 i.e. incompressible flow and is why it is not used for incompressible flow.

CFX solver is a pressure-based AMG coupled solver which means it works for all flow speeds.

Jon

Re: Oid fashion look of FLUENT
 

From my modest point of view (I am not a proficiency user in Fluent), I thing a fancy GUI would only add memory consumption, and RAM is very valuable when we talk about CFD.

Re: Oid fashion look of FLUENT
 

BTW Jon,

I never saw my incompressible simulation diverging on Fluent, i even tried it with natural convection but no luck, it just does not diverge.

As far as solvers are considered fluent gives you options as: segregated pressure based solver coupled density based solver with AMG and Full multigrid and with non iterative and iterative versions (for unsteady cases),

and as far as i recollect all the books related to multigrids mentions that Full multigrid performs better than AMG.

As far as cfx-amg solver is considered, i would personally do not want that, since if i have to use pressure based solver i can always use segregated solver where i can run, around 3 million cells with 3 GB RAM machine, which is currently a dream with CFX (where you put all the four coefficient in one single matrix and eat lot of memory). If i do need coupled solver for convergence, i can always chose coupled solver (since fluent gives me options). But i like your thinking that you are happy with whatever you have, i personally would be crying that my solver is not the best (and does not provide me options) if i were CFX user. Best of luck with CFX.

Re: Oid fashion look of FLUENT
 

For my case the RAM is very important, we hardly run any case smaller than 3 million cells, currently we are running cases around 6 million cells and next year with new machines i think we are going for simulations more than 10 million cells, i even prefer silent versions (with no gui) for such cases, but then it depends upon person to person and case to case.

Re: Oid fashion look of FLUENT
 

As I have understood things, the plan is to move Fluent into the new structure that were introduced with Flowizard. But this migration won't happen before v7. So we'll have to live with workspaces cluttered with fluent-windows for several more years...

Re: Oid fashion look of FLUENT
 

Fluent is great as it is to be honest! Look at STAR CD, God its complicated!

Re: Oid fashion look of FLUENT
 

Hi zxaar,

I prefer to talk about nodes, rather than elements. With 3 million tetrahedral elements it is possible to run it with CFX on a a 3Gb. With 3 million hexs it isn't. It also depends on the number of equations. I expect you to refer to a case with uvwpk and eps.

Regarding the RAM consuming GUI, we prepare the cases on our desktop PC's and run the cases on separate machines (Windows / Linux) in a batch process without any GUI. So, that argument does not hold.

Nevertheless, as mentioned before, I rather stick to my initial statement within this discussion, that FLUENT could use an "extreme makeover". My initial reservations when CFX was purchased by ANSYS appear to be dissolved in time.

Astrid

Re: Oid fashion look of FLUENT
 

I have never used STAR. How many STARS do you give its GUI? Is there an easy link to PDM software or FEM calculations?

Re: Oid fashion look of FLUENT
 

Astrid, as far as look and GUI and other makeover is considered i agree with you that there is a lot that could be improved, but Luca made a good point that there are lot of things which are of more importance than GUI that could be improved. My whole point is if I have a very good solver that converges well with my cases and within acceptable norms of accuracy, i do not much mind GUI. when you start to know what happens behind the doors of a solver GUI is not that important, I remember when i first downloaded the starCCM+ and started to work with it, my colleague asked me if i ever worked with it (since i just downloaded and performed two simple calculations). I never used starCCM+ but since i know how starCCM+ (or fluent or cfx) calculates the things, everything is just obvious. I never worked with CFX5.x also but i have read their documentation about solver, so i guess i can work with cfx also if you provide me that.

After writing a unstructured grid based FVM solver and spending one and half years of reading the docs of fluent cfx, starCD and doing lot of experientations with various grids (with fluent starCD, starCCM+) i have come to conclusion that fluent has the best solver that i could get commercially. It is the most stable solver i have seen.

We all wish that fluent or other solvers would improve, i my self have just started to work with pressure based - meshless method that i will try to implement in next few months, lets hope meshless solvers are the future.

Re: Oid fashion look of FLUENT
 

HI all what it said here is very interesting, I am personnally a proficient user of Fluent, and have had the occasion to open CFX and Stars. On solver basis, and other geeky stuff i let the expert talking and wont say anything. However concerning this GUI thing, there are 2 things to understand to explain the differences: Culture and Business Strategy. CFX is part of ANSYS, the major purpose of CFX is to give a higher value to their CAD package - For this reason CFX reflect the nice look and feel of ANSYS CAD package to offer a better integration. StarCD ... is mastering in marketing ... they are doing a great job selling that sh!t ... see the noise they made for StarCCM. Fluent, has clearly poor marketing compare to CFX and Star, and prefer to play on the robustness of their solver and a quality of support engineering that simply is amezing. More and more Fluent starts improving their marketing but this is also with the trust of their customer as a basis.

You can see here that fluent has no attach with what so ever CAD packages, kinda proving the poor integration of fluent with mesh generation, as well as a poor feel and look of their gui ... but as it has been said, they are working on a migration under python where you will have the choice using different font I think. A partnership with Catia V5 come on the way to create that missing link between CAD and Fluent. Also Flow Wizard is the sign that a better Mesh/Solver is on the way. The choice of Fluent to encourage a seperation Windows for GUI(calculation management) and Unix for Calculation runs is another proof of their intention to make their look and feel better. As far as their documentation i understand this documentation may be frustrating if you are a researcher trying to have super detailed information ... however academic do not pay, industry pay, and industry do not need that level of detail, on a pure engineering day to day use, this documention is great! if the documentation is not enought, the Fluent support will provide the missing informations.

Sorry for the length.