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

Loss Coefficient for Opening Boundary Condition

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 7, 2015, 18:15
Default Loss Coefficient for Opening Boundary Condition
  #1
New Member
 
Liliane Maciel
Join Date: Mar 2015
Posts: 1
Rep Power: 0
Liliane Maciel is on a distinguished road
Hello everybody,

I haven't realized yet if the loss coefficient (f) used by CFX is the same of the loss coefficient (\zeta) I have seen in other references. I have the opening discharge coefficient value and I have to set the loss coefficient in CFX, but I am not sure how those coefficients are related.Here is what I found in the Ansys Help:
Quote:
You can optionally specify a Loss Coefficient which can be used to model the pressure drop across a screen or other planar resistance at the opening. The pressure drop is calculated using:

\Deltap _{loss} = \frac{1}{2} f \rho Unē

where f is a specified Loss Coefficient and Un is the normal component of velocity at the opening boundary location.
and the relation I found in some papers between discharge coefficient (Cd) and loss coefficient (\zeta) is the following:
Cd = \frac{1}{\sqrt{\zeta}}

Is \zeta and f the same?

Last edited by Liliane Maciel; March 9, 2015 at 07:38.
Liliane Maciel is offline   Reply With Quote

Reply

Tags
loss coefficient

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
Opening Boundary Condition andreachan Main CFD Forum 11 March 19, 2013 17:46
No-slip condition for non-resolved boundary layer in open channel banks AlbertoVe Main CFD Forum 1 January 17, 2013 04:11
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
error message cuteapathy CFX 14 March 20, 2012 07:45
mass transfer coefficient for boundary condition niek Main CFD Forum 0 March 29, 2011 05:33


All times are GMT -4. The time now is 13:37.