CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Fluent UDF and Scheme Programming

Which macro yields the absolute pressure value?

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

Like Tree2Likes
  • 1 Post By CeesH
  • 1 Post By CeesH

Reply
 
LinkBack Thread Tools Display Modes
Old   April 13, 2015, 05:43
Default Which macro yields the absolute pressure value?
  #1
Senior Member
 
Join Date: Mar 2013
Location: B'lr
Posts: 126
Rep Power: 5
shivakumar is on a distinguished road
Hi,
From the solution data it is possible to obtain absolute pressure value at each node or cell center. In FLUENT manual I couldn't find the macro for absolute pressure.
Which macro yields the absolute pressure value.?

Thanks in advance
shivakumar is offline   Reply With Quote

Old   April 13, 2015, 05:59
Default
  #2
Senior Member
 
Cees Haringa
Join Date: May 2013
Location: Delft
Posts: 437
Rep Power: 9
CeesH is on a distinguished road
Isn't C_P(c,t) the absolute pressure?

If it is the relative, add the operating pressure to it and you're good to go right?
shivakumar likes this.
CeesH is offline   Reply With Quote

Old   April 13, 2015, 06:07
Default
  #3
Senior Member
 
Join Date: Mar 2013
Location: B'lr
Posts: 126
Rep Power: 5
shivakumar is on a distinguished road
Thanks for the reply.

I guess it is a static pressure value but I'm not sure..

But in the solution data, there are absolute, total, static pressure, etc values are available so only confused to access absolute pressure.
shivakumar is offline   Reply With Quote

Old   April 13, 2015, 06:46
Default
  #4
Senior Member
 
Cees Haringa
Join Date: May 2013
Location: Delft
Posts: 437
Rep Power: 9
CeesH is on a distinguished road
Maybe you want to check out the FLUENT user manual, section 7.14.

All pressures that you specify and all pressures computed or reported by ANSYS Fluent are gauge pressures.

So I'd guess the pressure reported by the macro is indeed a gauge pressure.

Then:
P_abs = P_operating + P_gauge. So, to get the absolute pressure, simply add the macro to the operating pressure.

To differentiate a bit more clear:

Static pressure: The static gauge pressure
Dynamic pressure: Velocity pressure (0.5*density*velocity)
absolute pressure: total static pressure; the gauge + operating pressure
total pressure: dynamic + static gauge pressure

Does this answer your question?
shivakumar likes this.
CeesH is offline   Reply With Quote

Old   April 13, 2015, 11:23
Smile
  #5
Senior Member
 
Join Date: Mar 2013
Location: B'lr
Posts: 126
Rep Power: 5
shivakumar is on a distinguished road
U have solved my doubt. I got it. Thank you very much ..
shivakumar is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
negative absolute pressure ahmadi FLUENT 0 May 23, 2014 08:54
InterPhaseChangeFoam ERROR shipman OpenFOAM Running, Solving & CFD 37 March 23, 2014 13:43
Difference between pressure, absolute pressure and Total Pressure shaswat CFX 1 September 6, 2012 06:12
Neumann pressure BC and velocity field Antech Main CFD Forum 0 April 25, 2006 02:15
about large minus absolute pressure richard FLUENT 3 December 6, 2003 10:39


All times are GMT -4. The time now is 17:22.