Calculating airflow with pressure and diameter?

AI Thread Summary
Calculating airflow from a tube into the atmosphere requires more than just pressure and cross-sectional area; additional factors like tube length and temperature are essential for accurate results. Upstream pressure is a key component, but without knowing the density and viscosity of the air, calculations remain incomplete. Companies producing spray nozzles often provide calculators that estimate flow rates based on upstream pressure, assuming a downstream pressure of one atmosphere. Therefore, it is not feasible to determine airflow using only the specified parameters. Accurate airflow calculations necessitate a comprehensive understanding of the system's conditions.
enanthate
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Hi.

Is there any way to calculate airflow out of a tube (into atmosphere) with only the pressure and cross sectional area of the tube?
 
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enanthate said:
Hi.

Is there any way to calculate airflow out of a tube (into atmosphere) with only the pressure and cross sectional area of the tube?
Are you talking about the upstream pressure? If so, you also need to know the length of the tube and the temperature (which determines the density and viscosity).
 
Chestermiller said:
Are you talking about the upstream pressure? If so, you also need to know the length of the tube and the temperature (which determines the density and viscosity).

Downstream.. Exit to atmosphere
 
Google is your friend (4.1)
'only the pressure' is weird if you mention 'tube' (link is for 'opening' , i.e. tube of length 0 )

Drat, slow typing again ..
 
enanthate said:
Downstream.. Exit to atmosphere
Then the answer to your original question is "no"
 
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enanthate said:
Hi.

Is there any way to calculate airflow out of a tube (into atmosphere) with only the pressure and cross sectional area of the tube?
Companies that make spray nozzles have calculators that will give you the flow rate given the pressure in the pipe leading to the nozzle (eg the upstream pressure) but they assume they are spraying into air (eg downstream pressure is 1 atmosphere).
 
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