jjn9128 wrote: ↑26 Dec 2021, 22:44
godlameroso wrote: ↑26 Dec 2021, 22:38
jjn9128 wrote: ↑26 Dec 2021, 22:35
Below ambient but yes. And without so many flow conditioners it will be much harder to do. These rules are quite tricksy, simple means you can't just bung on another widget to push the air about.
I meant at the entrance to the tunnels, the turning vanes at the tunnel inlet serve to increase the static pressure, shoveling air out of the way and by consequence creating a low pressure inlet at the main opening for the tunnels.
I don't agree but okay.
If the turning vanes are turning air, the pressure increases on the leading/outboard surface. Slowing down air raises its pressure, this is basic stuff. All diffusers work to increase air pressure, any time you make air turn it slows down, it's like going up a hill. The energy it takes for air to go around an obstruction reduces its kinetic energy.
The floor entrance is lower pressure, but only because the turning vanes are out-washing air raising the pressure outboard.
The tunnels work because the inlet is above static pressure and the outlet is at static, while the tunnels are below static. It's sort of like the pressure drop across an intercooler core. The pressure pre and after the heat exchanger are above static, the increased volume of the cooler creates a pressure drop that is partially recovered at the outlet.