[Grey]

Condition 1:
The model to be simulated is quite similar to a ducting system, which has openings in both horizontal and vertical fashion to suck wind in and connected to a common outlet. I want the wind to pass through the model, and the common outlet to have negative pressure(which means the wind passes inside the duct and exit at the outlet with the suction pressure I set to it). I think I'm not setting the boundary conditions right. So far nothing worked out yet. I want to simulate this as steady state but I'm having this hunch that this should be transient model as my intent is to have a suction motor inside to suck in the wind and pass it out through a common duct. The pictures include model and result with no suction pressure applied.

Condition 2:
There is a hollow cube in which a inlet duct from outside passes inside the cube and has openings at the end to distribute air inside the cube. This is quite similar to a centralized AC system that distributes air inside the room. Now we're applying the previous condition here i.e., there will be a suction pressure at the bottom of the channel which throws the air inside the room from its outlet.

P.S. These conditions were applied to models that were created on Rhino. When imported to Design Modeler, I get it as surface model. So I apply thickness and perform fill option to extract volume, and then I start to apply the boundar conditions. I've made numerous trials on varying the boundary conditions but I'm getting it wrong. I'm getting this thought that I'm trying to combine an open system like wind flow analysis and a closed system like air distribution inside a room through ducts. Thats where I'm losing it I think.
I understand that my knowledge on ANSYS is inadequate. I kindly request you to enlighten me.

Kindly suggest me best practices for these conditions of simulation. I'm looking for help on urgent basis.

Condition 1 Model: https://drive.google.com/open?id=1hj...LEoHxKiqD0pAEr

Condition 2 Model: https://drive.google.com/open?id=1qF...u6KZ5Pqwqfe2D-

First Model without suction applied: https://drive.google.com/open?id=1mn...2jXZISUEp4RV9S

Simple Illustration: https://drive.google.com/open?id=15-...qgOH-RQQJBjF3h