Appropriate Boundary conditions for jet flow in open domain
 

HI there!

I have been trying to solve flow past a bluff body in open domain. This particular problem poses some confusion to me regarding the boundary conditions imposed on the problem. The figs. for the open computational domain and physical domain are attached.

The bluff body would be placed near to the inlet (Velocity inlet) but in the open domain. I imposed pressure-far-field condition on wall 1, 2 and 3. Rest of the boundary conditions have been specified in the fig. 2.

Fig1. shows the physical domain we are trying to mimic. Flow from the cylinder exits into the open domain. The flow in the open domain (just outside the cylinder) is met by the bluff body kept in the center line.

Steady state simulation was adopted for the case with structured mesh (Fig.3). The following queries are bothering me and I would really appreciate if anyone could help me with it as I didn't find any other similar problem solved.

1. The size of the bluff body is 6 by 10mm. So is the domain size appropriate (mm) ?? :confused:. (x refers to 20 mm in the fig2).

2. Boundary condition used for the wall 1,2 and 3 was pressure-far-field and leads to divergence :mad:. What should be the appropriate BC?

Any help would be really appreciated :).