C_T(adjacent_cell) returns zero

momo_sjx · July 17, 2013, 13:23

Hi, I am a new user of UDF.
I am using VOF model for multiphase flow.
I want to access the temperature of adjacent cell of each cell.
There are some value return as zero (like 360 E-360);
Why?
What is this cell?
Thanks

Here is my code in Define_Adjust()

begin_c_loop (c,t)
{
c_face_loop(c, t, n)
{
f = C_FACE(c,t,n);
tf = C_FACE_THREAD(c,t,n);
if (!BOUNDARY_FACE_THREAD_P(tf))
{
c0 = F_C0(f,tf);
t0 = THREAD_T0(tf);
if (c0==c)
{
c0 = F_C1(f,tf);
t0 = THREAD_T1(tf);
}
Message("Temperature of adjacent cell:%g.\n",C_T(c0,t0));
}
}

vasava · July 23, 2013, 02:01

This might work:

temp1 = C_T(c0,t0);
Message("Temperature of adjacent cell:%g.\n",temp1);

momo_sjx · July 23, 2013, 18:53

Hi, thanks for this solution.
But it still does not work.
here is the output:
Temperature of neighbor cell is: 3.95253e-323;
The interesting thing is when I use serial simulation,
this problem disappear.

When I use parallel computation.
This problem appear.

What is the reason?

Thank you in advance.

vasava · July 26, 2013, 01:34

You must modify your UDF for parallel usage. Your must use !RP_HOST and !RP_NODE for that. You can look in to fluent manual for that.

momo_sjx · August 8, 2013, 10:50

Thank you very much. I found some documents on it.

July 17, 2013, 13:23	C_T(adjacent_cell) returns zero	#1
momo_sjx Member Sean (J.X.) Shi Join Date: May 2012 Location: US Posts: 34 Rep Power: 13	Hi, I am a new user of UDF. I am using VOF model for multiphase flow. I want to access the temperature of adjacent cell of each cell. There are some value return as zero (like 360 E-360); Why? What is this cell? Thanks Here is my code in Define_Adjust() begin_c_loop (c,t) { c_face_loop(c, t, n) { f = C_FACE(c,t,n); tf = C_FACE_THREAD(c,t,n); if (!BOUNDARY_FACE_THREAD_P(tf)) { c0 = F_C0(f,tf); t0 = THREAD_T0(tf); if (c0==c) { c0 = F_C1(f,tf); t0 = THREAD_T1(tf); } Message("Temperature of adjacent cell:%g.\n",C_T(c0,t0)); } }

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July 23, 2013, 02:01		#2
vasava Senior Member Paritosh Vasava Join Date: Oct 2012 Location: Lappeenranta, Finland Posts: 732 Rep Power: 22	This might work: temp1 = C_T(c0,t0); Message("Temperature of adjacent cell:%g.\n",temp1);

July 23, 2013, 18:53		#3
momo_sjx Member Sean (J.X.) Shi Join Date: May 2012 Location: US Posts: 34 Rep Power: 13	Hi, thanks for this solution. But it still does not work. here is the output: Temperature of neighbor cell is: 3.95253e-323; The interesting thing is when I use serial simulation, this problem disappear. When I use parallel computation. This problem appear. What is the reason? Thank you in advance.

July 26, 2013, 01:34		#4
vasava Senior Member Paritosh Vasava Join Date: Oct 2012 Location: Lappeenranta, Finland Posts: 732 Rep Power: 22	You must modify your UDF for parallel usage. Your must use !RP_HOST and !RP_NODE for that. You can look in to fluent manual for that.

August 8, 2013, 10:50		#5
momo_sjx Member Sean (J.X.) Shi Join Date: May 2012 Location: US Posts: 34 Rep Power: 13	Thank you very much. I found some documents on it.