Air flow through a 2" orifice
Air flow through a 2" orifice
(OP)
Hi,
I need to calculate the air flow through a 2" wall penetration between 2 rooms based on pressure difference of up to 1" of water. I am assuming that the penetration can be modeled as 2" round edge orifice. Crane Tech paper 410 provides the necessary equation for calculating the air flow for compressible and incompressible fluids.
My question is do I need to include the expansion factor Y and assume compressible flow or not.
Any help would be appreciated
Thanks
I need to calculate the air flow through a 2" wall penetration between 2 rooms based on pressure difference of up to 1" of water. I am assuming that the penetration can be modeled as 2" round edge orifice. Crane Tech paper 410 provides the necessary equation for calculating the air flow for compressible and incompressible fluids.
My question is do I need to include the expansion factor Y and assume compressible flow or not.
Any help would be appreciated
Thanks





RE: Air flow through a 2" orifice
RE: Air flow through a 2" orifice
If you had rooms with absolute pressures approximately atmospheric, expansion would only be (14.7 + 0.036)/14.7 that's only 1.002 x the volume in the lower pressure room.
**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Air flow through a 2" orifice
You can use incompressible fluid flow equation, as suggested by BigInch. The best method to assess the leakage is Blower-Door Test.