{"id":276098,"date":"2023-03-23T10:52:56","date_gmt":"2023-03-23T10:52:56","guid":{"rendered":"\/forum\/forums\/reply\/276098\/"},"modified":"2023-03-23T10:56:35","modified_gmt":"2023-03-23T10:56:35","slug":"276098","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/276098\/","title":{"rendered":"Reply To: Fluent UDF: Passing information to a face loop within a cell loop"},"content":{"rendered":"

<p> <\/p><p> <\/p><p>Thanks for the advice! Are you able to elaborate or link me to the documentation on how to serialize the cell loop and pass information to the other nodes?<\/p><p>For context, I am trying to build a solar ray tracer for cells to determine which cells are “shaded” and which cells are “exposed”. The built-in solar ray tracer in Fluent only works on surfaces but not on interior cells. I’ve considered using a diffuse radiation model but I found it to be very unreliable.<\/p><p>In my current serial code, I trace a ray from every cell centroid, and then loop over all the wall faces. I then run an algorithm to determine whether the ray intersects each face. If it intersects a face, a UDM value of 1 is assigned to the cell, and then it skips to the next cell in the loop and repeats the process. This is why I need to pass information (i.e. the cell centroid) from the begin_c_loop<\/strong> into thread_loop_f<\/strong> and begin_f_loop<\/strong>.<\/p><p>I understand the computation will be expensive. However, for each cell, there will be several “if” conditions that need to be satisfied before it considers each face (e.g. a simple one being that the cell centroid would need to be below the face centroid), so the actual computation will hopefully be manageable. I can also consider dividing the mesh into boxes, and determine whether the ray intersects a box before looping over the faces that lie within the box. However, I’m currently just trying to get a basic code working in parallel before I consider ways to reduce the computational time.<\/p><p> <\/p><p> <\/p><\/p>\n","protected":false},"template":"","class_list":["post-276098","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