Defining CG MOTION
 

Hi all,

I am trying to model a fluid body.
One wall of the fluid body will be fixed, while another wall at the other extreme will be subjected to linear and angular velocity in the x,y and z direction (I suppose this requires the 6dof solver).
However when I try to run the simulation, there isn't any velocity values assigned to the 3 directions. I am thinking it may be because I did not define the CG in my code or on fluent properly. Have attached my code right here, would appreciate if anyone can advise me on this. Thank you!

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#include "udf.h"
#include "math.h"
#include "dynamesh_tools.h"

DEFINE_CG_MOTION(valve, dt, vel, omega, time, dtime)

{

/* reset velocities */
NV_S (vel, =, 0.0);
NV_S (omega, =, 0.0);


/* compute velocities formula */

vel[0]=0.0011; /* computing linear velocities */
vel[1]=0.001225;
vel[2]=0.0042;
omega[0]=-0.09774;
omega[1]=0.317214;
omega[2]=0.15184346;
printf("\n");
printf("\n rotational_speed = %g \n",omega[2]);

}

hi
I am the student of fluid mechanics and now I am studying on fluid project. The subject of my project is about blade turbine that Oil radially impacts to the turbine blades by a nozzle, causing the turbine to spin. I have a problem in modeling of turbine that I don’t know how to obtain moment of inertia of blade and fluid and how to relate this challenge to the Cg motion until I can model this turbine in fluent software. Please help me
Thank for your attention

I had the same issue. Make sure that you have assigned UDF in dynamic mesh options to every boundary of the cell zone, including interior. In my case I have forgotten about interior.