## Fluids

#### Fluent – Air velocity problem / verification

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• bugroakold
Subscriber

Hello,

I'm currently trying to simulate air flow in a pretty big room (3.4m x 1.85m x 4m). The function of this room is to create artifical tornado. It is planned to be achieved by using 4 masts with 6 small inlets each. Inlets are faced towards inner circle as shown in the figure below:

• Rob
Ansys Employee
Given the jet is not confined it will slow as it's dissipated in the larger domain. Use vectors on the horizontal plane through the jet to see what's going on and adjust the scale: blue is 0-10m/s so you may find you've lost the resolution. On the pressure outlet use the Radial Equilibrium option. Also, which turbulence model are you using? Read the theory on the different models before you changed anything.
• bugroakold
Subscriber
I've used vectors and contours

The velocity around the cente
Also, English is not my native language, so could you please elaborate what do you mean by "jet" and "not confined"? I assume jet = this rectangular hole from which air is blown into the room, but I can't grasp the second term.
I 've actually tried few models rather randomly, now I'm using GEKO turbulence model.
• Rob
Ansys Employee
GEKO will need some tuning (and the correct choice of parameters) so avoid for now. Read up on the k-omege and RSM models.
Jet is the fast moving fluid, and "not confined" is because the jet flows into open space. The above is a good start but try plotting on the z-plane. You'll see how the jet behaves then. As you're in Fluent also have a look in the Velocity results section, tangential, radial and axial components will be useful when you come to write up.