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

What pressure profile to provide to ABAQUS ???

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

Reply
 
LinkBack Thread Tools Display Modes
Old   January 24, 2006, 18:00
Default What pressure profile to provide to ABAQUS ???
  #1
thomas
Guest
 
Posts: n/a
Here is a quick question. I am having a high velcoity (60 m/s) flow impacting onto some blades. After convergence i am extracting the pressure values onto the blade to provide it to abaqus to check the stress contour. Which Pressure Profile Should I use ? The Static Pressure Profile or the TOTAL Pressure Profile - Static + Dynamic?.

In my head it is the Total Pressure profile to account the pressure due a fluid momentum but i am asking for a comfirmation here. THANKS in adavnce !!!
  Reply With Quote

Old   January 24, 2006, 18:55
Default Re: What pressure profile to provide to ABAQUS ???
  #2
Thomas
Guest
 
Posts: n/a
You should use the pressure that is seen by the blade. If the blade is not moving you should use the total pressure.

thomas
  Reply With Quote

Old   January 24, 2006, 19:23
Default Re: What pressure profile to provide to ABAQUS ???
  #3
thomas
Guest
 
Posts: n/a
Thanks effectively the blade is not moving, so i will use the total pressure ! THANKS MUCH !
  Reply With Quote

Old   January 25, 2006, 04:11
Default Re: What pressure profile to provide to ABAQUS ???
  #4
Luca
Guest
 
Posts: n/a
I'm sorry but to me you should use the static one. Luca
  Reply With Quote

Old   January 25, 2006, 09:46
Default Re: What pressure profile to provide to ABAQUS ???
  #5
thomas
Guest
 
Posts: n/a
OK, xould you explain to me why you think so ? .. also maybe theword blade is not the right term, i am not studying a pump or anything rotative just a high velocity flow around a wall. Thanks for your quick answer !

  Reply With Quote

Old   January 25, 2006, 09:53
Default Re: What pressure profile to provide to ABAQUS ???
  #6
Luca
Guest
 
Posts: n/a
Have you ever seen a Cp (pressure-coefficient) plot of an aerfoil? Remember how Cp is defined. Total pressure is just a definition. So sorry for my short answer... Luca
  Reply With Quote

Old   January 27, 2006, 05:33
Default Re: What pressure profile to provide to ABAQUS ???
  #7
Razvan
Guest
 
Posts: n/a
Dear fellow Fluent users, we are talking about hypersonic flows, multiphase, deforming meshes, extremely complicated heat transfer, but we seem to have forgotten even the basics of fluid mechanics!!!

Mr. Luca is wright, you should use static pressure! Why? The answer is simple: imagine only how these two pressures are measured (static and total).

- static pressure is measured using a gauge with a hole parallel to the main flow direction, so it measures actually the pressure that THE WALL THAT WOULD HAVE EXISTED THERE (instead of the hole!!) SHOULD HAVE FELT, with the fluid IN MOTION.

- total pressure is measured using a gauge with a hole normal to the flow direction, at the end of a tube, so it actually measures THE SAME FLUID pressure, in the same spot, but STATIONARY, so total pressure is the pressure that a wall would feel if the fluid was completely stationary.

Some people may get confused a little, and say something like: what about the stagnation point? Well, that's THE ONLY POINT where Pstatic=Ptotal in a moving fluid.

I hope this was a good enough explanation.

Best wishes, Razvan
  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
UDF to define or adjust pressure??? engahmed FLUENT 0 July 6, 2010 17:19
circumferential pressure profile on outlet -> error when writing results mhsr CFX 0 August 14, 2009 10:54
unsteady pressure, temp profile without a udf mahi FLUENT 0 November 10, 2008 04:53
FLOW AROUND A PLATE_NEGATIVE ABSOLUTE PRESSURE???? tania FLUENT 11 March 23, 2004 09:51
pressure gradient term in low speed flow Atit Koonsrisuk Main CFD Forum 2 January 10, 2002 11:52


All times are GMT -4. The time now is 16:40.