UDF problem in multiphase boundary condition
 

Hi everyone!

I am simulating a transient multiphase problem in which I have gas and solid particles in a duct and from on of the outlets I want just let particles go out and not the air, so I tried to test a UDF for my purpose (written below) but it does not work and it seems that even after 13 seconds the particles are in the first cell of the material inlet.

I look forward for your kind comments, solutions or correction for my UDF file.

/************************************************** *****************/
/*This UDF is an implementation of the degassing boundary condition*/
/************************************************** *****************/

#include "udf.h"
#include "sg.h"
#include "sg_mphase.h"
#include "flow.h"
#include "mem.h"
#include "metric.h"

DEFINE_SOURCE(Inlet_x_velocity, cell, thread, dS, eqn)
{
real source;
Thread *Material_outlet = THREAD_SUPER_THREAD(thread);

source = -C_R(cell,thread)*C_VOF(cell,thread)/CURRENT_TIMESTEP ;

C_UDMI(cell,Material_outlet,0) = source;

dS[eqn] = -C_R(cell,thread)/CURRENT_TIMESTEP;

return source;
}

Check your settings and maybe geometry.
 

There is no wrong of your code compared to UDF manual. I suppose that you had some setting mistake, can you give the set up step by step.