Continuity Residuals
 

I am solving a two-phase VOF model with phase change (both heat and mass transfer across the interface). Just wondering if the residual values of continuity could be greater than 1? I am observing residuals with values close to 1e+03 but they seem to be decreasing and eventually reaching to the convergence value (set at 1e-04).

The residual is scaled by the maximum of first a few iterations (default 5). It the residual keep on growing after that then it could be larger than 1. It does not matter if it converges finally.

Thanks again, Thomas. I kinda had an idea that it is converging but its taking a lot of iterations each time step. Since my evaporation rates and difference in densities of liquid and vapor are high at the liquid-vapor interface, my initial residuals might be high.

This is not related to this particular forum but do you know how to impose a constant temperature inside one of the phases (in a VOF model) throughout the simulation (every iteration of each time step)? I tried the following but it did not work.

DEFINE_ADJUST(somename,domain)
Thread *lt = pt[liquidphaseindex];

begin_c_loop_all(c,t)
{
if (C_VOF(c,lt) == 0.0)
{
C_T(c,t) = 329;
}
}
end_c_loop_all(c,t)

The temperature inside that phase is decreasing to a much lower value and after a few iterations reaching to zero Kelvin.

One quick question, why
instead of
Due to physical and numerical diffusion, the
does not necessary be zero even for a cell taken up by one specific phase. You should use
instead.

Could I loop over threads of a specific phase? I thought it generally gives a segmentation error. Let me try it anyway.

About the tolerance, I agree. The volume fraction may not necessarily be zero or one even though the cell is completely filled with a specific phase. Thanks for the extra tip.

BTW, if I use
begin_c_loop_all(c,lt)
instead of
begin_c_loop_all(c,t)
how can I access the mixture threads for temperature macro
C_T(c,t)

Could I use C_T(c,mt)? Here "mt" is a new thread different from "t", and specified as:

Thread *mt = THREAD_SUPER_THREAD(lt);