solidification/Melting for pure component in V12.0.16
For Pure component solidificaiton ( when Tl = Ts) the temperature and liquid fractoin field is not correct. This is a bug and is fixed in R12.1. The workaroudn is: 1. Provide slightly higher liquidus temperature than solidus temprature. (can be of the order of 0.1) 2. A better workaroudn is to use the below UDF for pure component solidifcation. use this UDF as a energy source in fluids panel. #include "udf.h" #define slope_max 1e+2 DEFINE_SOURCE(energy_src,c,t,dS,eqn) { if(!rp_unsteady) return 0.; else { Material *m = THREAD_MATERIAL(t); real liqf = C_LIQF(c,t); real latent_heat = MATERIAL_PROP(m,PROP_melting_heat) ; real tliq = MATERIAL_PROP(m,PROP_tliqidus); real slope = slope_max * latent_heat ; real dt = CURRENT_TIMESTEP; if(liqf >0. && liqf < 1.0) { C_T_S(c,t) = C_R(c,t)/dt*tliq*slope*C_VOLUME(c,t) ; C_T_AP(c,t) += C_R(c,t)/dt*slope*C_VOLUME(c,t) ; } return 0. ; } } This is fixed in 12.1.x 

