Would you rather...?

Joan Vilalta · October 11, 2019, 04:47

Hi,
I'm doing a research project about the aerodynamics in a F1 car and I'm going to do an airfoil simulation to get the drag and lift coefficient and forces.
Would you rather using Ansys CFX or Ansys Fluent to do the simulation of an airfoil? Why? What are the differences between them?

Gert-Jan · October 11, 2019, 06:36

You can get accurate answers from both packages. Provided you do the simulation correct.

Carlo_P · October 11, 2019, 08:44

Hey,
both are widely used and well tested.
Maybe for external aerodinamic Fluent it would be a little better, also becasue you can use poly mesh.
On the other hand, CFX is easier to learn and to use and for my experience a little faster to reach the convergence.
Fluent on the other hand is the future, since CFX will be eliminated in the future (maybe in 10 yesrs, but the trend is this one), so maybe it would be better to learn Fluent.

Cheers,
Carlo

karachun · October 11, 2019, 09:41

Quote:

also becasue you can use poly mesh

Polyhedra is hardcoded into CFX.

Quote:

CFX will be eliminated in the future (maybe in 10 yesrs, but the trend is this one)

'CFX Lived, CFX Lives, and CFX Will Always Live'

Gert-Jan · October 11, 2019, 09:56

Indeed. CFX is node based solver. Fluent is a cell based solver.
Taking a tet mesh into CFX, it creates a polyhedra around each node, ending up in a polymesh solution. The solver does this for you.
Taking the same tet mesh into Fluent, it will take the cells as such, ending up in a tet solution, which is not very accurate. To obtain the same accuracy as in CFX you need to convert the tet mesh into a polyhedra mesh. Fluent can do this, but is not always succesfull. Alternatively, don't create tet meshes anymore, but only polyhedra. Or hexmeshes.

CFX is hardly maintained. All good things are transferred to Fluent. And that's a pity. CFX is more foregiven than Fluent. Can't stand the message: "The fl process ........."

October 11, 2019, 04:47	Would you rather...?	#1
Joan Vilalta New Member Joan Vilalta Mor Join Date: Oct 2019 Posts: 10 Rep Power: 7	Hi, I'm doing a research project about the aerodynamics in a F1 car and I'm going to do an airfoil simulation to get the drag and lift coefficient and forces. Would you rather using Ansys CFX or Ansys Fluent to do the simulation of an airfoil? Why? What are the differences between them?

October 11, 2019, 09:56		#5
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	Indeed. CFX is node based solver. Fluent is a cell based solver. Taking a tet mesh into CFX, it creates a polyhedra around each node, ending up in a polymesh solution. The solver does this for you. Taking the same tet mesh into Fluent, it will take the cells as such, ending up in a tet solution, which is not very accurate. To obtain the same accuracy as in CFX you need to convert the tet mesh into a polyhedra mesh. Fluent can do this, but is not always succesfull. Alternatively, don't create tet meshes anymore, but only polyhedra. Or hexmeshes. CFX is hardly maintained. All good things are transferred to Fluent. And that's a pity. CFX is more foregiven than Fluent. Can't stand the message: "The fl process ........." karachun likes this.

October 11, 2019, 06:36		#2
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	You can get accurate answers from both packages. Provided you do the simulation correct.

October 11, 2019, 08:44		#3
Carlo_P Senior Member Carlo_P Join Date: May 2019 Location: Italy Posts: 176 Rep Power: 8	Hey, both are widely used and well tested. Maybe for external aerodinamic Fluent it would be a little better, also becasue you can use poly mesh. On the other hand, CFX is easier to learn and to use and for my experience a little faster to reach the convergence. Fluent on the other hand is the future, since CFX will be eliminated in the future (maybe in 10 yesrs, but the trend is this one), so maybe it would be better to learn Fluent. Cheers, Carlo