Reply To: Melting and solidification process for different boundary condition& time period

[sumeet94]

Sir, I wrote a UDF regarding the above-stated problem, which is given below,

#include "udf.h"
real pcm_tavg;
real gc_tavg;

#define T_S 494  /*pcm solidus temperature*/
#define T_L 514  /*pcm liquidus temperature*/
#define h 10 /*heat transfer coefficient*/
#define T_amb 300 /*ambient temperature*/

/* CALCULATING THE PCM DOMAIN VOLUME WEIGHTED AVERAGE TEMPERATURE*/

DEFINE_EXECUTE_AT_END(pcm_domain_average_temperature)
{
statement
----------
pcm_tavg = -----;
}

/* CALCULATING THE GLASS COVER AREA WEIGHTED AVERAGE TEMPERATURE*/

DEFINE_EXECUTE_AT_END(glass_cover_average_temperature)
{
statement
----------
gc_tavg = -----;
}

/* APPLYING CHARGING AND DIS-CHARGING BOUNDARY CONDITION */
 
DEFINE_PROFILE(bound_condition,thread,position)
{
    real x[ND_ND];
    real current_time = CURRENT_TIME;
    int current_time_step = N_TIME;
    real current_time_step_size = CURRENT_TIMESTEP;
    real total_time = current_time_step*current_time_step_size;
    current_time=0;
 #if !RP_HOST
        face_t face;
        while(current_time<=total_time)
        {
            begin_f_loop(face,thread)
            {
                if(pcm_tavg>=T_L)
                {
                    Message("pcm completely melts, pcm_Tavg = %g\n",v_w_tavg);
                    while(current_time<=total_time)
                    {
                        begin_f_loop(face,thread)
                            {
                               if(pcm_tavg<=T_S)
                                {
                                    Message("pcm completely solidifies, pcm_Tavg = %g\n",v_w_tavg);
                                    break;
                                }                                    
                                else
                                { 
                                    F_CENTROID(x,face,thread);
                                    F_PROFILE(face,thread,position) = h*(T_amb-gc_tavg);
                                }
                            }
                        end_f_loop(face,thread)
                       current_time = current_time + current_time_step_size; 
                    }                    
                }
                else
                {
                F_CENTROID(x,face,thread);
                F_PROFILE(face,thread,position) = 20000;
                }
            }
            end_f_loop(face,thread)
            current_time = current_time + current_time_step_size;
        }
    #endif    
}

First, I calculated the PCM domain volume-weighted average temperature and area-weighted average temperature for the glass cover outer surface, respectively, using the UDF - DEFINE_EXECUTE_AT_END macros, as shown in the UDF above. These two UDFs work fine.  

The change of boundary condition is done by using the DEFINE_PROFILE macro. Initially, the flux value applies as per the condition. But, the problem arises when the PCM average temperature exceeds the T_L; it doesn't enter the if condition statement of the 1st while statement; rather, it continues with the else statement. Can you please suggest why the if statement doesn't work?