[Jonathon_L]

Hi all,
I am using UDF to simulate the erosion of fluid in the tube against the wall. I built a model with rectangular bulges on the wall and wanted to use UDF to make dynamic mesh reduction to simulate erosion.

In my wear equation, the amount of erosion is related to the angle at which the fluid impacts the wall, so I need to get the angle between the wall and the direction of fluid velocity. I know that I can use F_C0(f,t) to select the cell that is in contact with the fluid domain, but how can I select the face in the cell that is in contact with the fluid?

thread_loop_c(t,domain)
{
begin_c_loop(c,t)
{
c0=F_C0(f,t);
c_face_loop(c0,t,n)
{
F_AREA(A,f,tf);
velm=NV_MAG(vel);
Am=NV_MAG(A);
cos=NV_DOT(vel,A)/velm/Am;
alpha=asin(cos)*180/3.1416;
}
}
}

[AlexanderZ]

in your code you've made loop over cells,

thread_loop_c(t,domain) 
{ 
begin_c_loop(c,t) 
{

but to use c0=F_C0(f,t); you need loop over faces

thread_loop_f(t,domain) 
{ 
begin_f_loop(f,t) 
{

best regards

[Jonathon_L]

Originally Posted by AlexanderZ

in your code you've made loop over cells,

thread_loop_c(t,domain) 
{ 
begin_c_loop(c,t) 
{

but to use c0=F_C0(f,t); you need loop over faces

thread_loop_f(t,domain) 
{ 
begin_f_loop(f,t) 
{

best regards

Thank you very much! I'll try.