[aronsyu]

Dear all

I am trying to calculate mass fraction but not sure what macro can use.

There is a macro named "C_YI" I found , I think that I can use it .(?)


model description:

1. laser hits on the metal powder, and it will melt when it received enough of energy.

2. no chemistry reaction

Can anyone help me to solve this problem?

Thank you.

[CeesH]

Hi Aaron,

There is a distinction between multi-species and multi phase. The first is for multiple miscible species, the latter for immiscible. The C_YI macro is for multi-species (miscible) situations, where the simulation is single phase but you are tracking the mass fraction of some dissolved substance (this is enabled via the species equation, not via multiphase). For multiphase (Eulerian, VOF, etc.) the macro to find a phase volume fraction is C_VOF

Best regards
Cees

[aronsyu]

Originally Posted by CeesH

Hi Aaron,

There is a distinction between multi-species and multi phase. The first is for multiple miscible species, the latter for immiscible. The C_YI macro is for multi-species (miscible) situations, where the simulation is single phase but you are tracking the mass fraction of some dissolved substance (this is enabled via the species equation, not via multiphase). For multiphase (Eulerian, VOF, etc.) the macro to find a phase volume fraction is C_VOF

Best regards
Cees

Hi, Cees,

Thanks for your correction, I am deriving "mass fraction" from "volume fraction".
But here is the error occurred,

When I trying to use C_R(c,t) to export density of metal, error occurred.

Can you help me to point where is the problem it may happen?

Should I write it down in "DEFINE_SOURCE" or another macro?

Thank you

Aaron

--------my UDF code below----------

DEFINE_SOURCE(laser_source, c, t, ds, eqn)
{
Thread *pt; //VOF defination solid phase
int phase_index = 0; //VOF defination solid phase


face_t f;
real time,source,sourceup;
real radq,conv,epsi,delfc, testing, rho_s;


real x[ND_ND],s[ND_ND];

pt = THREAD_SUB_THREAD(t,phase_index);
//VOF defination solid phase
real rho = C_R(c,pt);
time = RP_Get_Real("flow-time");

C_CENTROID(x,c,t);
C_UDMI(c,t,rho) = rho_s;

return source;