[lilistar-8216]

Hi,
I'm trying a calculation of fuel droplet evaporation using ANSYS Fluent 19.1.
I complied this UDF to change heat generation rate at the wall between solid and fluid zone. Also I compiled UDS for getting T-derivative of mass fraction.
I can compile and load these UDFs, and initialize but when calculation starts, the error : "999999 mpt_accept error accept failed no such file or directory " occurs and calculation stops.

How should I solve this problem??

/*my UDF for boundary condition */
#include "udf.h"
#include "mem.h"

#define A 74.0
#define B 0.323
#define W_d 142.2
#define T_c 617.4


DEFINE_PROFILE(heat_profile, thread, i)
{
Domain *d = Get_Domain(1);
Thread *t = Lookup_Thread(d,11);
cell_t c;
real mf_d, T, T_r, v_heat,mf_dt, rho;
real time = CURRENT_TIME;
begin_c_loop_all(c, t) {
if (time == 0.0) {
F_PROFILE(c, t, i) = 0.0;
}
else {
rho = C_R(c, t);
mf_d = C_UDSI(c, t, 0) * rho;
T = C_T(c, t);
T_r = T / T_c;
v_heat = A * exp(-B * T_r) * pow(1 - T_r, B) / (W_d * 1000);
F_PROFILE(c, t, i) = mf_d * v_heat;
}
end_c_loop_all(c, t)
}

}


/*UDF for UDS*/

#include "udf.h"


DEFINE_UDS_UNSTEADY(uds_1,c,t,i,apu,su)
{

real physical_dt, vol, mass, phi_old;

physical_dt = RP_Get_Real("physical-time-step");

vol = C_VOLUME(c, t);

mass = C_YI_M1(c,t,55);

*apu = - mass * vol/ physical_dt;

phi_old = C_STORAGE_R(c,t,SV_UDSI_M1(i));

*su = mass * vol * phi_old/physical_dt;
}

[AlexanderZ]

Why do you include udf.h file to times? delete this

/*UDF for UDS*/
#include "udf.h"

put your case file and compiled library into the same folder.

did you allocate memory in FLuent GUI for UDS?

best regards

[lilistar-8216]

Dear AlexanderZ,

Thanks for answering. I actually make UDF for heat generation rate and UDF for UDS respectively. That's why it include "udf.h" two times.

I can't understand the meaning "did you allocate memory in Fluent GUI for UDS"...
I tried to set UDM but it didn't work.
How should I allocate memory for UDS?
regards

[AlexanderZ]

delete this

/*UDF for UDS*/
#include "udf.h"

put both your functions into one file, libraries are included once in the head of file

to allocate memory for UDS in Fluent GUI go to USer-defined -> scalars -> number of UDS change to 1.

best regards

[lilistar-8216]

allocate memory for UDS in Fluent GUI go to USer-defined -> scalars -> number of UDS change to 1.

I tried this and set UDF into unsteady function. I also tried to put both functions into one file but the same error happened.

regards

[AlexanderZ]

change physical_dt = RP_Get_Real("physical-time-step"); to

physical_dt = CURRENT_TIMESTEP;

put all files into 1 folder.
check again, was your UDF compiled wiouth error or not?

best regards

[lilistar-8216]

change physical_dt = RP_Get_Real("physical-time-step"); to
Code:
physical_dt = CURRENT_TIMESTEP;
put all files into 1 folder.

I tried this but It also didn't work.

check again, was your UDF compiled wiouth error or not?

I could compile UDF because there is no error.

regards