I am trying to simulate the motion of SiC particles in an air filled enclosure in FLUENT. The left and right walls are at 373 K and 273 K respectively and top and bottom walls are adiabatic. Natural convection with just air is behaving fine but I am not able to insert the particles into my enclosure. I want them to be already present in the enclosure at t=0. The particles need to be one way coupled with air and will move as air rotates in the enclosure. I want to perform particle tracking in the Lagrangian frame after different intervals of time. Please help me with how to add 1000 particles with a random initial distribution and zero initial velocity in the enclosure without having to inject them.