[lquarshi]

I am injecting particles using the surface injector, and with the parcel release type I used number of particles. I then put in the number of particle in a parcel which is 0.998. I read in the manual that number of particles in a parcel could be an integer, which makes it better to inject required of particles to meet the expected total mass of particles.

I am using the Rosin-Rammler distribution. During the post-processing, I was hoping to see single particles going through the domain but I see about 3-4 particles clustered. When I zoom out I could see they are individual particles clustered in line. I don't see any injection when I use the stagger-option.
What could be the cause of this that the particles are being clustered in line?

I have attached some pictures for my set up.