CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Programming & Development

rhoPimpleFoam Initial Density

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 22, 2020, 07:03
Default rhoPimpleFoam Initial Density
  #1
New Member
 
Join Date: Jul 2020
Posts: 5
Rep Power: 5
kamakura is on a distinguished road
Dear Foamers,

I am trying to calculate a compressible fluid using rhoPimpleFoam(OpenFOAM1806).
My question is the calculation of density.
I use the ideal gas law (perfect Gas) to calculate density.
Do you know how the density at the start of the calculation is calculated?
It was found that the density was calculated from the pressure, gas constant, and temperature, and the initial value of the pressure was read in createfields.H.
I didn't know how the initial temperature values ​​were read.

Thanks in advance.
kamakura is offline   Reply With Quote

Old   December 22, 2020, 15:36
Default
  #2
Senior Member
 
Michael Alletto
Join Date: Jun 2018
Location: Bremen
Posts: 615
Rep Power: 15
mAlletto will become famous soon enough
https://cfd.direct/openfoam/user-gui...hermophysical/

See equation of state
mAlletto is offline   Reply With Quote

Old   December 22, 2020, 23:46
Default
  #3
New Member
 
Join Date: Jul 2020
Posts: 5
Rep Power: 5
kamakura is on a distinguished road
Dear mAlletto,

Thank you for your reply. I apply perfectGas to calculate the density.

I understand that the density field is calculated using pressure field, temperature field, and gas constant at any time step (after starting time loop).
I can not understand that how the density is calculated BEFORE starting time loop.
In the createfields.H, pressure is initialized, then, density is initialized.
But where Temperature is initialized?

I apologize for the difficulty in reading in my poor English.
kamakura is offline   Reply With Quote

Old   December 23, 2020, 02:22
Default
  #4
Senior Member
 
Michael Alletto
Join Date: Jun 2018
Location: Bremen
Posts: 615
Rep Power: 15
mAlletto will become famous soon enough
The temperature is calculated in the thermopackage from the energy.
https://caefn.com/openfoam/temperature-calculation
mAlletto is offline   Reply With Quote

Old   December 23, 2020, 02:44
Default
  #5
New Member
 
Join Date: Jul 2020
Posts: 5
Rep Power: 5
kamakura is on a distinguished road
Dear mAlletto,

Thank you for your reply.

Thanks to the link you pasted, I understand the existence of a function that transforms energy into temperature.

At first of the calculation, temperature is initialized using the function.

Thank you for your kindness.
kamakura is offline   Reply With Quote

Reply

Tags
compressible, density, rhopimplefoam

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Free surface issues with interDyMFoam for hydroturbine oumnion OpenFOAM Running, Solving & CFD 0 October 6, 2017 14:05
High Courant Number @ icoFoam Artex85 OpenFOAM Running, Solving & CFD 11 February 16, 2017 13:40
pimpleFoam: turbulence->correct(); is not executed when using residualControl hfs OpenFOAM Running, Solving & CFD 3 October 29, 2013 08:35
SLTS+rhoPisoFoam: what is rDeltaT??? nileshjrane OpenFOAM Running, Solving & CFD 4 February 25, 2013 04:13
pisoFoam with k-epsilon turb blows up - Some questions Heroic OpenFOAM Running, Solving & CFD 26 December 17, 2012 03:34


All times are GMT -4. The time now is 22:54.