CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

UDS flux through wall and interior face.

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

LinkBack Thread Tools Search this Thread Display Modes
Old   July 26, 2006, 03:07
Default UDS flux through wall and interior face.
Posts: n/a

I am modeling a UDS through two fluid zone,between them is a interior face,and I specify zero to UDS value at the top wall bundary ,and a non-zero flux to the bottom wall.

problems come when I use the following code to calculate UDS flux through each wall:


c0 = F_C0(f, tf);

tc0 = THREAD_T0(tf);

F_AREA(area, f, tf);




diff_flux += NV_MAG(area)*uds_diff_ap*(F_UDSI(f,tf,0)- C_UDSI (c0,tc0,0))/ds*A_by_es;


I thought I specified boundary values and there should be UDF flux through the wall,but I got zero flux,someone know the reason?

and I also use

face_value0 = C_UDSI(c0,tc0,0)+NV_DOT(C_UDSI_G(c0,tc0, 0),dr0);

face_value1 = C_UDSI(c1,tc1,0)+NV_DOT(C_UDSI_G(c1,tc1, 0),dr1);

to calculate the interior face value,it turned out face_value0 differs from face_value1,and suggestions?
  Reply With Quote

Old   July 26, 2006, 05:40
Default Re: UDS flux through wall and interior face.
Posts: n/a
Does fluent calculate any uds flux? You can use //report/uds-flow to get the uds flow rates at boundraries.

The difference between the two face vaules is usual for FVM based codes. If you need the face value you can use (face_value0+face_value1)/2 as a first estimate.

  Reply With Quote

Old   July 29, 2006, 03:54
Default Re: UDS flux through wall and interior face.
Posts: n/a
yes Rom,you are ture,Fluent does not calculate any uds flux.

my intention was to made some modifacation with UDF to make sure that at the interior face the uds flux from zone 1 equals the flux into zone 2,however fluent deal different zone interface(specified as interior) with node value and approximation(zone 1 and zone 2 specified with different uds diffusivities),this thus cause the flux into through the interface extreamly big,how should I elimite this gradiant effect?

about the zero flux from the top wall and the bottom wall ,it is due to the print presion set in pritf(),and it is not zero.
  Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 20:12.