## Fluids

#### How to set the wall boundary condition?

• tungseng99
Subscriber

Hi guys, I am trying to study the airflow pattern and temperature distribution within a greenhouse. Solar ray tracing with DO model is applied. There are velocity inlet and pressure outlet. The sidewalls and top wall of the external flow field are set as symmetry walls.

I have a question about setting the wall boundary condition of the ground around the greenhouse. I understand that if I have modeled the solid volume, then I don't have to put the wall thickness. And when the wall thickness is specified, there will be a thickness that grows away from the wall into the fluid. So, I'm a little bit confused and lost in this case whether do I need to put a wall thickness for the ground? Or do I actually need to model the solid volume of the ground?

It would be much appreciated if anyone could help me out with this.

• DrAmine
Ansys Employee
You have actually two approaches: either you model the ground as solid so you resolve the thickness or you rely on modeling it through a couple of ways. One of them is just to provide thickness and to have sort of resistance normal to the wall.
• tungseng99
Subscriber
I have another question is that I have a concrete floor inside the greenhouse with 10 cm thickness, I want to study the surface temperature distribution on the floor as well. Can I apply shell conduction on the floor?
• Rob
Ansys Employee
You can. However, if you expect the thermal mass of the slab and soil to have an effect on the result you may want to include the slab as a solid and soil as a thin wall with a thickness.
• tungseng99
Subscriber