[daylen]

Hi, i´m simulating flow through a box with vents containing 6 spheres, what i don´t understand is that the results from the simulations shows very high pressure drop between inlet and outlet (42000 kinematic pressure at inlet and -10000 at outlet). is the simulation realistic?

simpleFoam case:
https://www.dropbox.com/s/pntr90nqtc...foam2.zip?dl=0

[Tobermory]

Yes, it makes sense. Look at the velocity and you'll see that you have a velocity of around 150m/s through each vent. So the (kinematic) dynamic pressure is Pd=0.5 * U^2 = 11,250. If we assume a loss coefficient of Cd=2 for the simple orifice, then that gives a dP of 22,500 per baffle, i.e. 44,500 between inlet and outlet. That matches the pressure you quoted.

The real question is: why do you have a hurricance passing through your vents? The answer: check your boundary condition. You are forcing in air at 6.68m/s at the inlet, and then this constructs do at the vents ... to 150m/s.

So, have a rethink about your BCs. The good news is that the code appears to be working nicely.

[daylen]

ok thanks for your answer