February 8, 2016, 13:12
CFX vs. FLUENT
Join Date: Jun 2009
Rep Power: 8
This topic never stops showing up in the forum. Let me help you make it clear.
1. By CFD Code
- FLUENT : UK college > Creare (US) > Fluent (US) > Ansys
- CFX : UK Nuclear Research > AEA Technology (UK) > ASC (Canada, CFX-TASCflow) > Ansys
- STAR-CD : UK college > CD-Adapco
- FineTurbo : Brussel college (Prof. Hirsch) > NUMECA
2. By Solver Type
- Segregated : Pressure-based Method of FVM : FLUENT, STAR-CD
- Continuity, momentum and energy equations are solved sequentially.
- Pressure is later corrected by Pressure-Velocity Coupling (like SIMPLE, SIMPLEC or PISO)
- Originally for incompressible flow, but extended to compressible flow
- Coupled : Time Marching of FVM : FLUENT (RAMPANT), FineTurbo
- Conservative vector forms in time and space
- Explicit (FineTurbo, FLUENT RAMPANT) or implicit (FLUENT) solver with multigrid
- Originally for compressible flow, but extended to incompressible using pseudo-compressibility factor
- Better accuracy in highly compressible flows (maybe controversial)
3. CFX is kind of unique
- CFX is a coupled solver, but needs the pressure-velocity coupling, too. It belongs to the Pressure-based group.
- CFX is fully implicit, relatively faster than FLUENT, but requiring much storage.
- CFX is a cell-vertex code, while FLUENT a cell-centered.
- CFX has a shape function borrowed from FEM to evaluate gradients, but FLUENT uses the staggered grid concept.
4. CFX vs. FLUENT
- CFX has more friendly GUI for turbomachinery users (that was a kind of business strategy for CFX-TASCflow to survive competing with FLUENT).
- FLUENT has traditionally more users in more general applications.
- Both are now good enough !
5. My recommendations
- If you simulate combustion, multi-phase or chemically-reacting flows, I'd go with FLUENT segregated.
- If you simulate a single phase turbomachinery flow, two options are recommended : CFX or FineTurbo. In this area, they are totally different animals. Try out both in your model through a comparison with reliable test data before making a decision.
- NUMECA FineTurbo grid generation package (Autogrid) has been frequently agreed more powerful and of higher quality, but the Post still looks not easy to love.
Last edited by turbo; February 8, 2016 at 15:58.