|
[Sponsors] |
April 21, 2010, 08:33 |
inital conditions
|
#1 |
New Member
Johannes
Join Date: May 2009
Posts: 16
Rep Power: 16 |
Hey everybody!
I desined 3 eulerian phases(Dodecane(L),Dodecane(G) and Nitrogen). At the beginning of my simulation there is just Dodecane(L) and Nitrogen. So how can I define where the inital position of the phases are? It's a 3dimensional simulation. The inital position just depends in z direction. So for example: z<=0.5 --> Nitrogen z>=0.5 --> Dodecane(L) Can anybody help me? thank you very much! Johannes |
|
April 22, 2010, 09:20 |
|
#2 |
Member
Vinicius Girardi
Join Date: Mar 2009
Location: Sao Paulo, Brazil
Posts: 80
Rep Power: 17 |
Hi Johannes,
You have to create a scalar field function such as: Initial Nitrogen: ($$Centroid[2] < 0.5 ) ? 1 : 0 Initial Dodecane: ($$Centroid[2] > 0.5) ? 1 : 0 at the Volume Fraction node, select it to composite and associate these field functions for each phase. You can also use the $$Position field function instead $$Centroid. Be sure that you mesh has a good quality in this region, and if possible, try to have the cells aligned in the division line. Regards, Vinicius |
|
April 26, 2010, 07:22 |
|
#3 |
New Member
Johannes
Join Date: May 2009
Posts: 16
Rep Power: 16 |
Thank you very much for your answer!
But for what is the "?" in the equation? And the [2] is for the z-axis? Best regards, johannes |
|
April 26, 2010, 07:25 |
|
#4 |
Member
Vinicius Girardi
Join Date: Mar 2009
Location: Sao Paulo, Brazil
Posts: 80
Rep Power: 17 |
The ? in the equation is the "if" condition, for example (condition) ? true : false.
The axis are x =[0], y=[1] and z=[2]. Vinicius |
|
April 26, 2010, 08:10 |
|
#5 |
New Member
Johannes
Join Date: May 2009
Posts: 16
Rep Power: 16 |
thank's a lot!
a last question: Does it matter i which order I define the three eulerian phases? Cause i still get a failure when I define Dodecane(L) and Nitrogen with a field function. The initial condition of Dodecane(G) is 0 and constant... Thanks, and best regards |
|
April 26, 2010, 08:56 |
|
#6 |
Member
Vinicius Girardi
Join Date: Mar 2009
Location: Sao Paulo, Brazil
Posts: 80
Rep Power: 17 |
The order that you create the phases just define the order you might input the data in some fields, like volume fraction... What is the error that appears?
|
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Wind turbine simulation | Saturn | CFX | 58 | July 3, 2020 01:13 |
Implementation of boundary conditions for FVM | Tom | Main CFD Forum | 7 | August 26, 2014 05:58 |
Fluent accuracy and boundary conditions | Paolo Lampitella | FLUENT | 0 | June 12, 2008 06:25 |
Boundary conditions? | Tom | Main CFD Forum | 0 | November 5, 2002 01:54 |
A problem about setting boundary conditions | lyang | Main CFD Forum | 0 | September 19, 1999 18:29 |