[ajitk350]

this is my code:

#include "udf.h"

double contact_line_position=0;
double time=0;
double theta_e_radian=(15.0*M_PI/180.0);
double dynamic_contact_angle=15.0;
int first_time=1;
double contact_velocity=0;
FILE *file;
double sum=0.0,R;


DEFINE_ADJUST(Contact_Angle_Update, domain)
{
int ID = 6;
Thread *thread = Lookup_Thread(domain, ID);
Thread **pt = THREAD_SUB_THREADS(thread);
cell_t c;
face_t f;
real x[ND_ND];
double max_x=0, f_Hoff_inverse, x_hoff,temp, Ca, volume;
int n;

sum=0.0;

begin_c_loop_all (c,pt[1])
{
if(C_VOF(c,pt[1])!=0 /*&& ABS(x[1]-0.000125)<1e-6 && ABS(x[2]+0.003)<1e-6 */)
{
C_CENTROID(x,c,pt[1]);
//printf("## x=%f y=%f z=%f vof=%f\n",x[0],x[1],x[2],C_VOF(c,pt[1]));
if(x[1]>max_x)
max_x=x[1];
}
sum+=C_VOF(c,pt[1]);
}
end_c_loop_all (c,pt[1])

R=sqrt(sum*1.0e-08/M_PI);
printf("max_x=%f R=%f contact_velocity=%f time=%f dynamic_contact_angle=%f sum=%f\n",max_x,R,contact_velocity,time,dynamic_co ntact_angle,sum);

if(first_time==0)
{
contact_velocity= (R-contact_line_position)/(RP_Get_Real("flow-time")-time);
contact_line_position = R;
time=RP_Get_Real("flow-time");
Ca = contact_velocity*1e-3/0.0728;
temp= 0.5-0.5 * cos(theta_e_radian);
temp= 0.5 * log( (1.0+temp)/(1.0-temp) );//atanh(0.5-0.5 * cos(theta_e_radian))
f_Hoff_inverse = -(9.78546 * pow( temp,1.416430594900850))/(12.819 * pow(temp,1.41643)-100.0);
x_hoff= Ca + f_Hoff_inverse ;
if(contact_velocity>=0)
dynamic_contact_angle= acos( 1-2*tanh(5.16*pow((x_hoff/(1+1.31*pow(x_hoff,.99))),0.706) ) ) *180.0/M_PI ;
else
dynamic_contact_angle= 2*theta_e_radian*180.0/M_PI -acos( 1-2*tanh(5.16*pow((x_hoff/(1+1.31*pow(x_hoff,.99))),0.706) ) ) *180.0/M_PI ;
file = fopen("file.txt", "a+");
fprintf(file,"max_x=%f R=%f contact_velocity=%f time=%f dynamic_contact_angle=%f\n",max_x,R,contact_veloci ty,time,dynamic_contact_angle);
fclose(file);
}
if(R>1e-18 && first_time==1)
{
contact_line_position = R;
time=RP_Get_Real("flow-time");
first_time=0;
file = fopen("file.txt", "a+");
fprintf(file,"max_x=%f R=%f contact_velocity=%f time=%f\n",max_x,R,contact_velocity,time);
fclose(file);
}
}

DEFINE_PROFILE(Contact_Angle_Set_Profile, thread,i)
{
face_t f;
begin_f_loop(f,thread)
{
F_PROFILE(f,thread,i) = dynamic_contact_angle;
}
end_f_loop(f,thread)
}

When I compile this UDF, I receive some error message such as:

Creating library libudf.lib and object libudf.exp
.obj : error LNK2019: unresolved external symbol __imp__RP_Get_Float referenced in function _Contact_Angle_Update
.obj : error LNK2019: unresolved external symbol __imp__n_phase_solver referenced in function _Contact_Angle_Update
.obj : error LNK2019: unresolved external symbol __imp__Lookup_Thread referenced in function _Contact_Angle_Update
libudf.dll : fatal error LNK1120: 3 unresolved externals

I use fluent 19.1 and Visual Studio 2008.
Need suggestions

[AlexanderZ]

open fluent from visual studio console and compile your code

[ajitk350]

Hello AlexanderZ,
I did it but it is not working.

[AlexanderZ]

i've compiled this code without any errors

[pakk]

Originally Posted by ajitk350

Hello AlexanderZ,
I did it but it is not working.

How do you compile? Which buttons do you click?

[ajitk350]

Thanks, it is working.

[pakk]

If you remember what you needed to do to get this working, please add it to help other people with this problem.

[ajitk350]

Hello Alexander Z
First of all, I would like to say thanks for helping me.
my code is running but I am no sure this code is correct or not for dynamic contact angle. could you please check my code?

I am a developing a model " DROPLET IMPACT ON THE SURFACE". Please help me.

[AlexanderZ]

I can't say you if your code works as you want or not
it depends on what you want and how you are hooking this functions.

this code works properly only on single core, parallel is not available (modifications required)

[ajitk350]

Hi Alexander Z
I want to activate the level set method with VOF in ANsys fluent 2020 R2. There is one option to activate the level set method directly. So, my question is, if I activate the level set method, will it work? or I will have to write UDF for CLSVOF ?

[ajitk350]

Dear Alexander Z

The code is running well on a single core. but, the code is working only static contact angle, not dynamic contact angle. could you please suggest to me what changes make dynamic contact angle instead of static contact angle?

[AlexanderZ]

I have no idea what you mean under dynamic contact angle

in code above dynamic_contact_angle is hard coded

double dynamic_contact_angle=15.0;

change this value and you will get other result

[ajitk350]

Dynamic contact angle means static contact angle should be changed when droplet spreading and recoiling. So, when I fixed the static contact angle, the dynamic contact angle should be changed during the simulation. But, in my problem, dynamic contact angle is not changing. It becomes fixed like 15.0.