CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > NUMECA

reference pressure in Numeca

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

Like Tree1Likes
  • 1 Post By colinda1

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 26, 2021, 06:58
Default reference pressure in Numeca
  #1
New Member
 
wwcs
Join Date: May 2021
Posts: 4
Rep Power: 3
abuya is on a distinguished road
Hey, guys. I'm learning Numeca recently. I have a question about the reference pressure in Numeca. What is the meaning of it? If the reference pressure is 1atm, and the inlet total pressure is 2atm. Should I set the inlet total pressure to be 1atm (2atm-1atm) or 2atm?
abuya is offline   Reply With Quote

Old   July 28, 2021, 13:48
Default
  #2
Senior Member
 
Hamid Zoka
Join Date: Nov 2009
Posts: 277
Rep Power: 17
Hamidzoka is on a distinguished road
Hi;
In NUMECA Boundary values for pressure are absolute values and do not need to be expressed with respect to reference pressure.
The function of the mentioned reference pressure,together with reference temperature, is to calculate entropy and its value does not affect the results. As it is known, entropy is always measured with respect to a reference value and in thermodynamic processes its delta is important. So, These reference parameters can take any value.

Regards
Hamidzoka is offline   Reply With Quote

Old   July 29, 2021, 08:51
Default
  #3
New Member
 
wwcs
Join Date: May 2021
Posts: 4
Rep Power: 3
abuya is on a distinguished road
Quote:
Originally Posted by Hamidzoka View Post
Hi;
In NUMECA Boundary values for pressure are absolute values and do not need to be expressed with respect to reference pressure.
The function of the mentioned reference pressure,together with reference temperature, is to calculate entropy and its value does not affect the results. As it is known, entropy is always measured with respect to a reference value and in thermodynamic processes its delta is important. So, These reference parameters can take any value.

Regards
Thank you!
abuya is offline   Reply With Quote

Old   August 2, 2021, 04:06
Default
  #4
Senior Member
 
Colinda
Join Date: May 2012
Location: Brussels
Posts: 144
Rep Power: 12
colinda1 is on a distinguished road
I would like to add that apart from the entropy, the reference pressure is used at other places as well. This may be different for each solver. For example for the Fine™/Turbo solver this may be:
  • in the Boussinesq approximation for incompressible fluid,
  • in the outlet boundary condition for which the mass flow is imposed with pressure adaptation when the expert parameter MASPAO < 2,
  • in the definition of the heat transfer coefficient when the expert parameter HTCDEF is set to 2.

It is also used as a default gauge pressure for the preconditioning in case of low speed or incompressible flows.
Hamidzoka likes this.
colinda1 is offline   Reply With Quote

Reply

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
viscosity udf don't use correct temperature and strain rate rezvani Fluent UDF and Scheme Programming 8 May 27, 2021 06:40
[OpenFOAM.org] Not found many .so files when installing OpenFOAM 6 lengjun OpenFOAM Installation 1 November 8, 2020 02:25
Domain Reference Pressure and mass flow inlet boundary AdidaKK CFX 75 August 20, 2018 06:37
reference pressure and compressible flow bingo10 CFX 0 September 11, 2013 08:32
G95 + CGNS Bruno Main CFD Forum 1 January 30, 2007 01:34


All times are GMT -4. The time now is 21:40.