B.C. for ventilator in tunnel

Marat Hoshim

Hi,

could someone make some recommendations concerning the right choice of boundary conditions for the 2D flow in a tunnel driven by a ventilator.

The ventilator is placed in the middle of the tunnel. There should be no wind which means that with the ventilator turned off there is no flow in the tunnel. In the first try I set the static pressure at the entrance and the exit of the tunnel 0 Pa. But i could not reach a steady (periodic state) at the blades of the ventilator.

Assuming additional wind I prescribed the velocity at the entrance and an outlet an the exit. In this case the forces on the wings were periodical after 5 or 6 revolutions.

Unfortunately not in the case of no winds. Any idea will be appreciated !

Thanks, Marat