I want the 3000 particles' velocities are equal to the local fluid velocites (in a 2D domain). The particles are released uniformly at one cross section. How can i use UDF to get that? I don't want to use 'file' to achieve that. Thanks in advance.

why u dont want to use a file?

I want a uniform release of the particles within 0.0014m. There are more than 3000 thousand particles. I tried to use rake. But the maximum was just around 1000 points. So i am wondering whether i can use udf to achieve more than 3000 points within 0.0014 m.