confusion on how to write udf for density of a mixture solution in multiphase problem

Hirakjyoti · September 8, 2017, 10:57

Hi I am new to CFD and this forum. I am simulating a problem where an aqueous solution of LiCl wih mass fraction of licl 0.3(secondary phase) is used to dehumidify moist air (primary phase) and i need to write udf for density of the solution which is a function of mass fraction and temperature. I have gone through the udf tutorials but still I am struggling with this. The equation is attached below. Please help me in writing the udf.
where rho(0,1,2,3)are constants.

Hirakjyoti · September 11, 2017, 02:21

I have tried to write the udf, but i m not sure whether it is correct or not.I need help.

#include"udf.h"
DEFINE_PROPERTY(Variable_density_rho,c,t,C_Y3)
{
Thread*c_thread;
cell_t,c;
real C_Y3(c,t,3);
return C_R(c,t)=1000*((1+pow((C_Y3/(1-C_Y3)),1)*0.540966)+(-.30372*
(pow((C_Y3/(1-C_Y3)),2))+(.100791*(pow(C_Y3/(1-C_Y3)),3))));
}

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September 11, 2017, 02:21		#2
Hirakjyoti New Member Hirakjyoti Barman Join Date: Sep 2017 Posts: 7 Rep Power: 9	I have tried to write the udf, but i m not sure whether it is correct or not.I need help. #include"udf.h" DEFINE_PROPERTY(Variable_density_rho,c,t,C_Y3) { Threadc_thread; cell_t,c; real C_Y3(c,t,3); return C_R(c,t)=1000((1+pow((C_Y3/(1-C_Y3)),1)0.540966)+(-.30372 (pow((C_Y3/(1-C_Y3)),2))+(.100791*(pow(C_Y3/(1-C_Y3)),3)))); }