Stack Effect #13530
Unanswered
ShehabGamrah
asked this question in
Q&A
Stack Effect
#13530
Replies: 1 comment 1 reply
-
I suggest you perform a simulation with no fire and no ventilation. Look at |
Beta Was this translation helpful? Give feedback.
1 reply
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
-
I have some confusion regarding the neutral plane and its relation to the stack effect and the pressure reference point in my model. I’m simulating a fire in an apartment at ground level, with the environmental conditions unchanged. There’s a natural opening at the head of the stair (an open boundary condition), which acts as an inlet for air, while smoke rises through a natural shaft with an opening at the top (an open boundary condition). The velocity vectors seem accurate, with airflow entering through the stair opening and exiting from the top of the shaft.
However, I'm puzzled by the pressure slice through the shaft. The pressure appears highest at the top of the shaft, but shouldn’t there be a neutral plane where the pressure inside the shaft becomes higher than at the top? Also, does FDS account for a reference point, so that even though I’ve set the top as an open boundary condition, the pressure should still be lower than atmospheric pressure due to the height of the building? If flow moves from high pressure to low pressure, how is the pressure decreasing upwards, yet the flow direction is upwards?
Beta Was this translation helpful? Give feedback.
All reactions