[limowaagung11]

hi i have a design model quite a complex model about a ventilation duct inside a tunnel, I've made the model on CAD and imported it as IGS file in design modeler and have tried to simulate it on Ansys but the problem is the air is not flowing through the duct but otherwise it flow out (it makes no air flow inside the duct). I've imported duct as slice material, add frozen (It makes air didnt flow out from the duct), add material (similar case with add frozen).

[__sam__]

Originally Posted by limowaagung11

It makes air didnt flow out from the duct

First of all, your question is a bit vague, you might want to provide a diagram or explain the problem in more detail. Some questions you might want to ask yourself:

So do you have air volume inside your duct? If the duct is a closed, it will be modelled as a solid obstacle so make sure to check it's open so the mesher can place cells inside.

If you have mesh cells present inside the duct, have you checked how many cells it has been discretised with? If it's not got boundary layer cells and has a small number of large cells, it probably won't get flow through it because it's going to be seen as highly resistant due the domination of viscous forces.

How big is your duct? If it's a very small opening, it wouldn't surprise me that there is very little flow going through it as it may be highly resistant - you may need a fan inside to create a good enough pressure gradient.