|
[Sponsors] |
pressure-based solver VS density-based solver |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
New Member
baudolina85@hotmail.it
Join Date: Mar 2011
Posts: 2
Rep Power: 0 ![]() |
what is the difference between the "pressure-based solver" and the "density-based solver"?
|
|
![]() |
![]() |
![]() |
![]() |
#2 |
Member
Engr Adeniyi
Join Date: Jan 2011
Posts: 32
Rep Power: 16 ![]() |
I am not sure you are a biginner in Fluent (like me), but I think it might help to ask which Solver is better for your problem and why?
Going through the Fluent Manual, there are a lot of differences and depending on what you are solving. Unless your question is enumerating the differences, I think you may want to ask that question based on your problem type, for example Density Based solver is not available for Eulerian multiphase model framework, you will use the pressure based solver. You can do stuffs like solidification and melting model only with PBS. The PBS is said to employ a projection method algorithm, in this algorithm, mass conservation of the velocity field is obtained by solving a pressure/pressure correction equation in a way to satisty the continuity iteratively till convergence. The DBS attempts to solve the Continuity, Momentum, Energy and Transport eqns. in a coupled manner i.e. simulataneously. then followed by additional scalar transport equation. Some solution schemes may be available in PBS and not in DBS e.g. Central Diff. Scheme (CDS)., Bounded CDS. For your PBS, you can use (generally): the following pressure-velocity coupling algorithms: SIMPLE,SIMPLEC, PISO, Coupled and Fractional Step. Note also that PBS allows both Coupled and Segregated options. Hope this helps and not confusing ![]() |
|
![]() |
![]() |
![]() |
![]() |
#3 |
New Member
baudolina85@hotmail.it
Join Date: Mar 2011
Posts: 2
Rep Power: 0 ![]() |
i'm using fluent for modeling the dispersion of methane in air. the methane is introduced in air at 111K. I don't konw if is better use the density-based or the pressure-based models in the calculus.
|
|
![]() |
![]() |
![]() |
![]() |
#4 | |
Member
Engr Adeniyi
Join Date: Jan 2011
Posts: 32
Rep Power: 16 ![]() |
Quote:
The following features are available with the density-based solver, but not with the pressure-based solver: These are the "only" features available with the Density Based Solver: 1. **Real Gas Models (UDF and NIST) 2. Non-Reflecting BC 3. Wet-Steam Multiphase Model Otherwise (as in your case), you may want to use Pressure Based Solver. PBS is available for: Cavitation Model Volume-of-Fluid (VOF) Model ***Multiphase Mixture Model*** Eulerian multiphase model Non-Premixed Combustion Model Premixed Combustion Model Partially Premixed Combustion Model Composition PDF transport Model Soot Model Rosseland Radiation Model Melting/Solidification Model Shell Conduction Model Floating Operating Pressure Fixed Variable Option Physical Velocity Formulation for Porous Media Specified Mass flow rate for Stream-Wise Periodic flow The coloured/asterisked options above look to me like what you are trying to do. You may do a trial run on DBS to compare anyway. |
||
![]() |
![]() |
![]() |
![]() |
#5 |
New Member
mohsen tavakol
Join Date: Jan 2014
Posts: 1
Rep Power: 0 ![]() |
hello
i want to simulate a supersonic multi phase flow in fluent. the phase are air and steam as ideal gas. as i know, for simulating supersonic flows, we should use density based solver. but multi phase is disable in density based solver. please guid me. thanks. |
|
![]() |
![]() |
![]() |
![]() |
#6 |
New Member
uday
Join Date: Jul 2013
Posts: 9
Rep Power: 13 ![]() |
Hello
simulating supersonic flow and combustion together seems not possible with density based solver so is it ok to go ahead with pressure based solver? Can anyone help? Thanks |
|
![]() |
![]() |
![]() |
![]() |
#7 |
New Member
Utsav Jain
Join Date: Jul 2014
Posts: 5
Rep Power: 12 ![]() |
Uday,
Maybe its too late to answer but I wouldn't use pressure based solver for compressible flow problems (supersonic). Though density based solver can be used for both compressible and in-compressible solutions, I have seen that pressure based solver performs poorly for compressible problems. I hope this helps. When I do in-compressible combustion, I use pressure-based solver with coupled algorithm. |
|
![]() |
![]() |
![]() |
![]() |
#8 | |
New Member
Benoit D.
Join Date: Sep 2019
Posts: 2
Rep Power: 0 ![]() |
Quote:
Anyone an idea on how to proceed? Thank you! |
||
![]() |
![]() |
![]() |
![]() |
#9 | |
Senior Member
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,728
Rep Power: 66 ![]() ![]() ![]() |
Quote:
What's wrong with the pressure based solver? It works for supersonic flow. |
||
![]() |
![]() |
![]() |
![]() |
#10 |
New Member
Benoit D.
Join Date: Sep 2019
Posts: 2
Rep Power: 0 ![]() |
Thanks LuckyTran! That would be great. I've read in some places that the pressure based solver is not suitable for supersonic flows (inaccurate). I must admit I don't find anything about this in the user manual though, but I just wanted to be sure.
|
|
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Pressure based and Density based Solver | Xobile | Main CFD Forum | 39 | August 19, 2020 06:04 |
Using Density Gradient C_R_G(c,t), Pressure Based Solver | Anirudh_Deodhar | Fluent UDF and Scheme Programming | 1 | October 25, 2013 05:43 |
NRBC and pressure based solver | ageorg | FLUENT | 1 | August 28, 2009 07:11 |
why the solver reject it? Anyone with experience? | bearcat | CFX | 6 | April 28, 2008 14:08 |
Pressure vs Density based CFD solvers | Danie | Main CFD Forum | 0 | October 5, 2004 09:48 |