[bhanwar]

hey @ll....

i need to write a UDF to give outlet as reflecting surface for dispersed phase(solid particle)...if anybody havin any clue related 2 this....plzzz give ur valuable suggestion 2 me...




Bhanwar
m.tech @iitg

[johnwinter]

You can just change outlet BC from escape to reflect. no need of any udf

[bhanwar]

hey john..thnx for ur suggestion, u r right about the change of B.c but i think it is possible only for DPM case, well for Eulerian case is there any option rather then writin udf..and if no, plzz suggest me some idea about udf..


thanks in advance

bhanwar singh.

[johnwinter]

Hi Singh,

are you you using UDS for your case??

You can set values at the outlet is zero, something similar to wall.
if you think this didn't work. i have given a udf for you. Try using this

DEFINE_PROFILE(outlet_boundary,t,i)
{
#if !RP_HOST
face_t f;
cell_t c0;
Thread *t0;
begin_f_loop(f,t)
{
t0=F_C0_THREAD(f,t);
c0=F_C0(f,t);
F_PROFILE(f,t,i)=-C_UDSI(c0,t0,0);

}
end_f_loop(f,t)
#endif
}

[bhanwar]

hey john....

thnx for suggestion, i vl work on dat and very soon let u knw the result....

[tarangbulchandani]

Dear John,

Thanks for that UDF even I am working on that. But John I have a problem regarding DPM simulations. I am using Dense DPM in Ansys 13 and my volume fraction is coming very low which is not possible as the no. of particles are more so the volume of particles is coming more than the volume of column.

Dimensions of my column is (0.1mX0.02m).
Dimensions of solids is 0.005m

Kindly help me up.

Regards,
Tarang Bulchandani