[lalith]

Hi,
I need to model mass loss due to evaporation across a boundary in my domain. The source term is written for a cell and subsequently looped across the boundary. This is just a single phase flow model and I have tried to write a UDF for the mass source term as follows:

#include "udf.h"

/* CONSTANTS */
#define M 0.018;
#define hfg 2600;
#define R 8.314;
#define pi 3.14;
#define pref 101325;
#define Tref 373.15;
#define pv 15828;
#define Tv 343;


/*Source Term for evaporation from a boundary*/

DEFINE_SOURCE(mass_evap,c,t,dS,eqn)
{
real source, pv_eq, Tlv, vol, Acell ;
Thread *t_int;
face_t f_int;
Domain *domain;
domain=Get_Domain(1);
t_int=Lookup_Thread(domain,3); /*3 is the zone id for the boundary where source term is to be applied*/

begin_c_loop(c,t) /*to loop the source term over all the cells in the boundary*/
{
int i=0;
f_int=C_FACE(c,t,i); /*to get the global thread of faces for cell with index c and thread pointer t */

F_AREA(area,f_int,t_int); /*area of the boundary face of the cell */

Acell=NV_MAG(area); /*Magnitude of the area*/

Tlv=C_T(c,t); /*Temperature of the cell at the Boundary*/

vol=C_VOLUME(c,t); /*volume of the cell at the Boundary*/

pv_eq=pref*exp((M*hfg/R) * (1/Tref-1/Tlv)); /*expression of equlibrium pressure to be used in the m_evap expression*/

source= - Acell/vol * pow(2*M/(pi*R) , 0.5) * (pv_eq/pow(Tlv ,0.5) - pv/pow(Tv,0.5)); /*Source=(-m_evap*A_cell/V_cell)*/

dS[eqn]=- Acell/vol * pow(2*M/(pi*R) , 0.5) * pv_eq * (1/pow(Tlv,2.5) - 0.5/pow(Tlv,1.5) ); /*Derivative of the source term*/

}
end_c_loop(c,t)


return source;
}



I am not able to resolve the errors obtained after compiling.
Please help and guide.

[Wholemeal]

Please start your own thread.

[Moderator note: moved this line of discussion from this thread: http://www.cfd-online.com/Forums/flu...tax-error.html]

[pakk]

And if you start a new thread, please include the errors that you had. That will make it many times easier for us to find the problem.