|May 18, 2012, 11:30||
CG Motion UDF Problem
Join Date: Apr 2012
Posts: 2Rep Power: 0
I have been working in the past few days trying to understand UDFs but i think i've reached a dead end...
This is what i'm trying to do:
I'm just trying to simulate the flow around a body wich is moving up and down with a sinusoidal law of motion. To do this i have written my UDF just as is shown below:
DEFINE_CG_MOTION(object_mov, dt, vel, omega, time, dtime)
real a, w, pi;
pi = 3.1415;
/* define motion variables */
a = 0.05; /* 0.05m movement amplitude */
w = 2 * pi * 2; /* 2Hz frequency */
/* define object movement law */
vel = 0;
vel = -a * w * sin(w*time);
vel = 0;
I have no problem interpreting this UDF into Fluent. However, when defining the dynamic zone the following warning appears:
"Warning: incorrect cg motion UDF wing on zone 4 (assuming no motion)"
Do you have any clue why could this be? is my UDF correctly written?
Looking forward to your answer.
|June 2, 2012, 01:21||
Join Date: Mar 2012
Posts: 17Rep Power: 5
your missing a math header, try using these:
In addition, define an intermediate (i.e. "real v = 0") variable for the motion:
v = -a * w * sin(w*time);
vel = v;
hopefully it will solve your problem...
|August 1, 2012, 06:58||
Join Date: Jul 2012
Posts: 1Rep Power: 0
|udf cg motion|
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