Pressure Outlet - Effect of domain
 

Hello

I am modeling a conjugate heat transfer problem in STARCCM.
Inlet - Velocity Inlet
Outlet - Pressure Outlet

Flow - Laminar, Low R, Steady

As i change the distance between the trailing edge of the fin and outlet, P-inlet keeps on changing. I started with very small distance between Trailing edge of fin and outlet and then kept on increasing it. I did 6 simulations with different distance between Trailing edge of fin and outlet. I expect constant P at inlet after some value of this distance between Trailing edge of fin and outlet but its not the case. Aim is to get pressure drop. The lateral boundaries around outlet are symmetry planes. There is no recirculation at the outlet.

Any Suggestion ? Help

Thanks

Please plot the pressure with distance and see the trend. It should converge to a fixed value. Pressure outlet need to be placed at a location where geometric effects and viscous effects are negligible. In subsonic flow, outlet boundary will hold the input pressure and adjust the inlet boundary pressure. If you don't know the static pressure at the outlet at given location, better to move as far as possible.

Thanks duri for the information. I shall do some simulations with increased domain length for the outlet section. Will let you know.

Thanks

The distance from Trailing edge of the fin and the outlet section was not enough. P at inlet not changing now for distance between TE of fin and outlet section more than 4L, L is the length if the fin.

Thanks