Marangoni stress, help!!
 

Hi!everybody, now I will go to simulate on the heat transfer and fluid flow in the weldpool. As a boundary, I must add Marangoni stress to the weldpool surface, so Marangoni stress are expressed as follows: tau=del(sigma)=d(sigma)/dT del(T). I want to know where Marangoni stress are added? thanks in advance!

Re: Marangoni stress, help!!
 

I am working in nearly same field. I would like to know one thing. How to apply moving heat source. As specially, when you are trying to simulate 3-D problem.

My guess to your question is: Fluent calculates marngoni stress and add it on defined or calculated surface. What user need to prescribe is surface tension gradient.

I am not sure, if my answere help you or not..

best luck...

G

UDF code for moving heat source
 

Guess I am too late to the party haha ... Incase anyone still needs the moving heat source code.

#include "udf.h"

DEFINE_PROFILE(heat_source_profile, thread, position)
{
real x[ND_ND];
face_t f;
real current_time;
real Q = 1; // Define your heat source magnitude (Watts)
real rx = 30e-6; // Define your desired values for rx, ry, rz (meters)
real ry = 75e-6;
real rz = 30e-6;
real A;
real vel = 4e-3; // velocity @ m/s
real PI = 3.1416;
real x_pos;
real x_start = 0.0; // Set your desired starting position in x (m)
real y_start = 0.28e-3; // Set your desired starting position in y (m)
real z_start = 0.1e-3; // Set your desired starting position in z (m)



real x_local, y_local, z_local; // Declare local coordinates

current_time = CURRENT_TIME;
A = (6 * sqrt(3) * Q) / (PI * sqrt(PI) * rx * ry * rz);

x_local = 0.0; // Initialize x_local outside the loop
y_local = 0.0; // Initialize y_local outside the loop
z_local = 0.0; // Initialize z_local outside the loop

begin_f_loop(f, thread)
{
F_CENTROID(x, f, thread);

// Transform global coordinates to local coordinates
x_local = x[0] - x_start;
y_local = x[1] - y_start;
z_local = x[2] - z_start;

x_pos = vel * current_time;




// Compute the heat source function value

F_PROFILE(f, thread, position) = A * exp(-3 * (pow(x_local - x_pos, 2.) / pow(rx, 2.) + pow(y_local, 2.) / pow(ry, 2.) + pow(z_local, 2.) / pow(rz, 2.)));


}
end_f_loop(f, thread)
}