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

The viscosity field

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 27, 2001, 12:03
Default The viscosity field
  #1
Mehdi BEN ELHADJ
Guest
 
Posts: n/a
In PHOENICS code, the density field can be calculated in SEM or in HOL methods as follows:

RHO = RHOG * (1-VFOL) + RHOL * VFOL (it's logical)

G: for Gaz

L: for Liquid

VFOL: Volume Fraction of Liquid

but

why ? the viscosity field is calculated as follows:

ENUL = ENULG * (1-VFOL) + ENULL * VFOL
  Reply With Quote

Old   May 27, 2001, 13:50
Default Re: The viscosity field
  #2
silver
Guest
 
Posts: n/a
Look to the one-fluid formulation. To be prefectly correct the Indicator function (VFOL) is suppose to be a heavyside (step) function . so RHO is NOT a mixture but is EITHER a gas or liquid. this is also true for viscosity. Now we introduce our VOF, replace our step function with a volume intergral and people attempt to place some physics where we have averaged them all out.

so... ----------------------------------------------------- Q.. why ? the viscosity field is calculated as follows:

A.. That is just what the final form of the equations

came to when we put all of our assumptions.. -----------------------------------------------------
  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
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
problems after decomposing for running alessio.nz OpenFOAM 5 April 20, 2011 08:44
How to access custom Scalar Field in viscosity model caw OpenFOAM Running, Solving & CFD 0 March 26, 2008 12:11
Problem with rhoSimpleFoam matteo_gautero OpenFOAM Running, Solving & CFD 0 February 28, 2008 07:51
The viscosity field Mehdi BEN ELHADJ Phoenics 3 June 12, 2001 06:21


All times are GMT -4. The time now is 02:43.