Particles tracking and time-dependent bc in transient analisys
 

Hi everybody.
I'going to simulate a sorter that separate cotton flakes from impurities. Flakes are immersed in an air stream, and an high pressure nozzle - driven on-off by an optical sistem- blows the impurities away from the main stream.
My questions are:
1- How to define a time dependent velocity inlet (V=0 if t<=2s; V=100 for 2,0s<t<2,1s and v=0 if t> 2,1s)
2- How to define a particle tracking starting at a specific time in a transient simulation (non two way copuled)

Thanks to anyone so kind to answer to this.

1) This is a simple CEL expression. Have a look at the CFX tutorials as several of them cover CEL. Also look at the CFX reference manual, especially the sections on CEL.

2) The easiest way to do this is to do a simulation with no particle tracking, and then stop it at the transition point. Then start a new simulation using the first simulation as an initial condition and start the particle tracking.

But you should not need to do this. You can make the particle rate a CEL expression of time such that it is off until the transition time then your rate after that. This is just a simple CEL expression.

Thankyou so much Glenn!
I'm following your suggestions