Regarding transient turbulent flow model
 

Hi everybody,

I have been working on transient flow.Attached photo is to show both fluid zones and material (attached photo cross section 1/2) ( orange one: fluid zone), yellow one : material) (air enters from downward)

I just wanna to do flow simulation in post-processing.Before starting the setup in Fluent I have some answers.(I just wonder whether or not some holes are used in flow )

1) material CAD part is it necessary? ( outer surface of orange one will already be chosen ''wall'' by my own in some few days).That's way yellow one (material) is it necessary ?

2) This system is working on some time interval ( something like 3 seconds :working , 2seconds : stopping ) and how can i spesify it in transient turbulent flow model?

Kind Regards,