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

Help with Boundary Conditions

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 6, 2007, 03:34
Default Help with Boundary Conditions
  #1
chun wee
Guest
 
Posts: n/a
Hi,

I have problem in assigning BC for propeller simulation. I use fan BC to represent the propeller. I draw a tube isolating the fan surface. The BC is pressure inlet --> fan --> pressure outlet and the skin of the tube is symmetry.

Am I using the right BC?

I have Thrust vs RPM data from experiment. I can calculate the induced velocity and pressure jump using momentum theory.

I set the P operating as 1 atm. I notice that the P total in inlet should be around 1 atm and at inlet the P static is 1 atm, whereas the P total is unknown.

What should I put in gauge pressure column at Pressure inlet and outlet BC?

Right now, I keep it 0. It gives me wrong physical characteristics. the velocity is almost uniform everywhere, while the Velocity at oulet (V advance is 0 for hover condition) should be 2x the velocity at the fan surface.

I think I have made a mistake....
  Reply With Quote

Old   October 6, 2007, 09:09
Default Re: Help with Boundary Conditions
  #2
jesse
Guest
 
Posts: n/a
1.formula to calculate P total in respective to mach number 2.operating number at inlet set to 0 when not big pressure drop 3.specify the BC at Propell in cell zone Fluid?(i am also not sure about that,cos so far i dealt not too much with propell)
  Reply With Quote

Old   October 6, 2007, 10:01
Default Help with Boundary Conditions
  #3
chun wee
Guest
 
Posts: n/a
Hi jesse,

Thank for your answer. Isn't that total pressure as M function is for compressible flow? I'm simulating incompressible flow since the velocity is very low. Have you tried similar model before? maybe you can share your experience.

  Reply With Quote

Reply


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
Impinging Jet Boundary Conditions Anindya Main CFD Forum 25 February 27, 2016 13:58
symmetry boundary conditions in cfx lost.identity CFX 41 May 22, 2013 08:21
OpenFOAM Variable Velocity Boundary Conditions NickolasPl OpenFOAM Programming & Development 2 May 19, 2011 06:37
[Netgen] boundary conditions and mesh exporting vaina74 OpenFOAM Meshing & Mesh Conversion 2 May 27, 2010 10:38
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues michele OpenFOAM Meshing & Mesh Conversion 2 July 15, 2005 05:15


All times are GMT -4. The time now is 11:28.