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flow conversion

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ushang70

Mechanical
Oct 11, 2003
7
i want to convert 1356 NM^3/Hr to M^3/Hr.it is very confusing, what is full form of NM^3/Hr. if any one have solution answer me.


cheers,

ushang
 
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Normal (or standard) volume per unit time is a convention. You get two people to agree on what the "standard" is and then everyone pretends that the gas is at that pressure and temperature. It is a useful surrogate for mass flow rate in that you can add Nm3 at any pressure to Nm3 at any other pressure and get a meaningful answer. The magnitude of "normal" is subject to contract negotiations and government regulations--there is no one value for each parameter that is always used.

Actual volume per unit time is the volume flow rate at actual conditions.

Mass flow rate is not dependent on pressure and temperature so:

m(dot) = q * [ρ] = qactual*[ρ]actual=qnormal*[ρ]standard

So if you have volume flow rate at standard conditions (which is what is almost always reported) and you want a velocity you have to convert to volume flow rate at actual conditions. The equation above shows you how:

qactual=qnormal*[ρ]standard / [ρ]actual

Then divide by flow area to get velocity. Always remember that any flow at normal or standard conditions is imaginary and not useful for very many engineering calculations.

David

 
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