Hi,everyone! I have writen a UDF，which can be interpreted well. it can run well and have an impact on temperature when i use Non-Iterative Time Advancement as transient controls in solver.But it didn't take a little effect on temperature when i use Frozen Flux Formulation as transient controls in solver.i dont know why. anybody can help me??? I want add a energy source in metal .the sources should be added at position of the free surface of melting metal.I mainly used VOF and solidification&melting model(I'd like to simulate the flow of melting metal under the influence of gravity). IN order to capture the free surface, i use the macro of C_VOF(The free surface cross all the cell where the volume fraction is different from 0 or 1).my UDF as follows. #include "udf.h"

DEFINE_SOURCE(cell_heat_source,cell,mixture_thread ,dS,eqn) {

real source;

int phase_domain_index = 0; /* primary phase index is 0 */

Thread *water_thread = THREAD_SUB_THREAD(mixture_thread,phase_domain_inde x);

if(C_VOF(cell,water_thread)<1&&C_VOF(cell,water_th read)>0)

{

source=25000000;

dS[eqn]=0;

}

else

source=dS[eqn]=0;

return source; }

thank you

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