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-   -   Does CFX is better than fluent on solving heat-transfer problems generally (http://www.cfd-online.com/Forums/ansys/109419-does-cfx-better-than-fluent-solving-heat-transfer-problems-generally.html)

williamchina November 16, 2012 22:00

Does CFX is better than fluent on solving heat-transfer problems generally
 
i want to solve some problems about heat-transfer but i don't know which on i should choose bettwen CFX and Fluent.The people around me are good at Fluid dynamics but not in heat-transfer.
Anyone can tell me which one should i choose firstly.
Thanks.

LuckyTran November 16, 2012 23:52

there's really not much difference. But Fluent is better, has more modelling options.

Far November 22, 2012 02:22

For heat transfer I usually go with Fluent just because I think it is easy to set-up and usually performs better. But as LuckyTran has mentioned there is really not much difference in available modules.

Just think why both codes are still available in the ANSYS CFD suit, because they have some advantage with respect to each other in different industries. For example CFX is more powerful in turbo-machinery and support GGI in better way than the Fluent and therefore you can can see more improvement in CFX for the turbo-machinery.

In latest release of Fluent solver technology is greatly enhanced and many options were developed specifically for Fluent to make it compatible to CFX in terms of convergence and some technology was also adopted from CFX.

Turbulence models were also exchanged between CFX and Fluent. For example SA model, DES and LES option were strong point of Fluent and on the other hand SST model and transition models were the strong point of CFX.

So finally they are converging on the solver technology but still differs in GUI, ease of use, and their impact in different industries.

cdegroot November 24, 2012 17:51

Quote:

Originally Posted by LuckyTran (Post 392650)
But Fluent is better, has more modelling options.

I really can't stand it when people make blanket statements like that. "Fluent is better". Really? Or do you just have more experience with it?

Both codes have their own strengths and since they both became ANSYS products a lot of the features have been shared. CFX does seem to be better for general grid interfaces and turbomachinery applications. I am sure there are also cases where Fluent is better as well.

Far November 25, 2012 02:32

Quote:

Originally Posted by cdegroot (Post 393991)
I really can't stand it when people make blanket statements like that. "Fluent is better". Really? Or do you just have more experience with it?

Both codes have their own strengths and since they both became ANSYS products a lot of the features have been shared. CFX does seem to be better for general grid interfaces and turbomachinery applications. I am sure there are also cases where Fluent is better as well.


Fluent's interface is much easier to use. Every thing is there from pre to post.


Experience counts a lot. Because there is learning curve for each code. So if you are good at Fluent does not make you good at CFX automatically. You have to spend some time.

Moreover every code behave differently and experienced person knows what does it mean. Whether he is making mistake or not. Take an example: In Fluent, residual level of 1e-3 is considered good convergence, but in CFX even 1e-4 is not considered good convergence.

Fluent is less sensitive to user input such as mesh and boundary conditions. But CFX will either work or not. But Fluent will never blow-up the simulation and it keeps on trying.

cdegroot November 25, 2012 10:27

Hi Far,

I do appreciate your opinion but I respectfully disagree with some of it. For me I find CFX more user friendly actually. I also find CFD post a much more powerful post processor than what Fluent offers. I also find CFX less sensitive to bad mesh quality (this makes sense especially for tet meshes which are much better represented by the control volume finite element discretization). I do find Fluent blows up often and the user has to restart with different relaxation factors and hope it works better. CFX has a convenient auto timestepping procedure that seems to work for the majority of problems.

I do really agree with your comment that experience is what counts though. An experienced user of either software can usually get a difficult problem to work because they know all of the tricks of that program. For me I am an expert user of CFX and an occasional user of Fluent so obviously I will choose CFX because I know it better and it is easier for me. It seems the opposite for you.

Far December 2, 2012 01:26

Can we check the quality of mesh in CFX pre or can we check the Y+ in CFX Pre:rolleyes:


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