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

Laminar Anisotropic Flow - Acetic Acid in Water Is Not Diffusing

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 16, 2017, 17:45
Question Laminar Anisotropic Flow - Acetic Acid in Water Is Not Diffusing
  #1
New Member
 
Lisa Antoine
Join Date: Jun 2017
Posts: 4
Rep Power: 9
antoinel is on a distinguished road
Acetic acid in water is not diffusing for an anisotropic laminar flow simulation. The model is a 200 m x 200 m domain. The viscous models are laminar and species transport. The fluid materials are acetic acid and water. For the anisotropic UDS diffusion the matrix components for XX and YY are 3 and 1, respectively. The diffusivity is 31.5 kg/m-s. The boundary condition type for each wall is outflow. The user-defined function for the initialization of the flow follows.
/************************************************** *********************
UDF for initializing contaminant distribution
************************************************** **********************/
#include "udf.h"
DEFINE_INIT(init_distrib_anisotropic,d)
{
cell_t c;
Thread *t;
int i;
real xc[ND_ND];
/* loop over all cell threads in the domain */
thread_loop_c(t,d)
{
/* loop over all cells */
begin_c_loop_all(c,t)
{
C_CENTROID(xc,c,t);
C_YI(c,t,0) = (1.0/4.0/3.141593/120.0/sqrt(0.09)/sqrt(0.03))*exp(-1.0*pow(xc[0] - 99.75,2.0)/4.0/0.09/120.0)*exp(-1.0*pow(xc[1] - 99.75,2.0)/4.0/0.03/120.0);
}
end_c_loop_all(c,t)
}
}
After running the simulation for ~ 980 seconds the diffusion is virtually unchanged. Why is the acetic acid not diffusing in the water? What am I setting up incorrectly?
Thanks,
Lisa
antoinel is offline   Reply With Quote

Reply

Tags
anisotropic, diffusivity, laminar, mass fraction, species transport


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
No liquid water exist in my Fuel Cell simulation fatchang FLUENT 19 October 15, 2018 15:27
Use of laminar model for a turbulent flow jcamilleri Main CFD Forum 1 July 6, 2014 07:54
Influence of mesh density on laminar flow Ricevind FLUENT 2 June 16, 2014 09:53
Boundary Layer of Laminar Flow over a Flat Plate Blasius_Pohlhausen_Crocco Main CFD Forum 12 September 30, 2013 18:35
Problems with BCs in muliphase flow with water falling from a reservoir Paul_l FLUENT 2 March 11, 2011 05:59


All times are GMT -4. The time now is 22:13.