{"id":378060,"date":"2024-08-13T06:15:47","date_gmt":"2024-08-13T06:15:47","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/378060\/"},"modified":"2024-08-13T06:15:47","modified_gmt":"2024-08-13T06:15:47","slug":"378060","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/378060\/","title":{"rendered":"Reply To: Laser Melting heat source UDF issue [FLUENT Crashing]"},"content":{"rendered":"

<p>Even if the gradient is negative , I am squaring and rooting the x,y,z gradients and adding them in UDMI 3 right? It aint supposed to be the issue. However when I tried writing the heat source using DEFINE_PROFILE and used begin_f_loop , it worked (although I couldnt add any multiplying factor and gradient UDMI) . I need to multiply the “factor” and “UDMI” in order to convert the surface heat source to volumetric heat source.<\/p><p> <\/p><p>CODE : ( This heats up both my gasesous and solid phase , which I dont want)<\/p><p> <\/p><div><div>#include “udf.h”<\/div><br><div>DEFINE_PROFILE(heat_source_profile, thread, position)<\/div><div>{<\/div><div>    real x[ND_ND];<\/div><div>    face_t f;<\/div><div>    real current_time;<\/div><div>    real Q = 120; \/\/ Define your heat source magnitude (Watts)<\/div><div>    real rx = 5.3e-5; \/\/ Define your desired values for rx, ry, rz (meters)<\/div><div>    real ry = 250e-6;<\/div><div>    real rz = 5.3e-5;<\/div><div>    real A;<\/div><div>    real vel = 0.1e-3; \/\/ velocity @ m\/s<\/div><div>    real PI = 3.1416;<\/div><div>    real x_pos;<\/div><div>    real x_start = 0; \/\/ Set your desired starting position in x (m)<\/div><div>    real y_start = 0.2e-3; \/\/ Set your desired starting position in y (m)<\/div><div>    real z_start = 0.1e-3; \/\/ Set your desired starting position in z (m)<\/div><br><div> <\/div><div>   <\/div><div>    real x_local, y_local, z_local; \/\/ Declare local coordinates<\/div><br><br><div> <\/div><br><div>   <\/div><div>    current_time = CURRENT_TIME;<\/div><div>    A = (6 * sqrt(3) * Q) \/ (PI * sqrt(PI) * rx * ry * rz);<\/div><br><div>    x_local = 0.0; \/\/ Initialize x_local outside the loop<\/div><div>    y_local = 0.0; \/\/ Initialize y_local outside the loop<\/div><div>    z_local = 0.0; \/\/ Initialize z_local outside the loop<\/div><div>   <\/div><div>    begin_f_loop(f, thread)<\/div><div>    {<\/div><div>        F_CENTROID(x, f, thread);<\/div><div>       <\/div><div>        \/\/ Transform global coordinates to local coordinates<\/div><div>        x_local = x[0] – x_start;<\/div><div>        y_local = x[1] – y_start;<\/div><div>        z_local = x[2] – z_start;<\/div><div>       <\/div><div>        x_pos = vel * current_time;<\/div><br><div>     <\/div><div>       <\/div><div>       <\/div><div>        \/\/ Compute the heat source function value<\/div><div>       <\/div><div>         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.)));<\/div><div>         <\/div><div>         <\/div><div>    }<\/div><div>    end_f_loop(f, thread)<\/div><div>}<\/div><\/div><\/p>\n","protected":false},"template":"","class_list":["post-378060","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t