UDS Unsteady with UDM
 

Folks,

I am trying to solve a UDS equation which has only the transient and the diffusive terms in it (no source or convective terms). This transient UDS equation should act in such a way that it smears a multiphase field variable (say, phi_old) and returns the newer multiphase field variable at the current time step (phi_new).

If I calculate phi_old and store it in a UDM location (say, C_UDMI(c,t,0)), how should I use this phi_old to calculate phi_new?

Thanks for your consideration.

Are you looking for C_UDSI_M1?

Well, I am aware that C_UDSI_M1 stores the variable from the previous time step but how to use the following:

At current time step, let's say:
C_UDMI(c,t,0) = C_VOF(c,lt)*C_T(c,t);
Now, for UDS equation:
phi_old = C_UDMI(c,t,0);

At future time (next time step):
C_UDMI(c,t,1) = phi_new*C_T(c,t);

If I use C_UDSI_M1, then how would I calculate C_UDMI(c,t,0) in the first place?

Does anybody know how to do this?