Using an array works, but you need to define it as a global variable, so the values are saved and available in the next time-step. The tricky part here is that you need to declare a length similar to your thread length (Number of faces in the thread). Otherwise, the code will crash. The advantage of F_UDMI is that Fluent declare it for every face. So, you don't worry about declaring the right length.nYes. You can declare upto 500 face memory. If you need to save 3 variables for every face, declare 3 memories. They are numbered 0,1,2 and you can rename them only once before calculations. nNo, Node is an object .. not an integer. it has an ID which is integer, but you can't replace it with the ID.nnIf you are good in using Matlab, I remember I watched a video on youtube that generated the define_grid_motion UDF from matlab. It won't be straight forward as the video was missing some critical details. But it might be helpful. Here are two videos, and you might find more.nnnnn