Np = 100/Re + 1.2 - 1000/(Re + 1000)
Np = 0.90
where:
Re (Reynolds number) = D2 x Rps x (Fluid Density/Viscosity)
where: D = Impeller distance in meters
Rps = Impeller speed as measured in revolutions per second
Fluid Density = As measured in kilograms per cubic meter (kg/m3)
Viscosity = As measured in Pascal seconds (centipoise/1000)
The flow number (Nq), sometimes called the Pumping Number (this is a dimensionless number), is determined by:
Nq = Q/(D3 x Rpm/60)
Nq = 0.81
where: Q = Flow in m3/second
D = Impeller distance in meters
Rpm = Impeller sped as measured in revolutions per minute
*Go thro.:
http://impeller.net/How can we calculate performance by impeller nos. of vanes,its gap, angle, diameter?Well, if you are going to cut and paste my work, you need to drop the answers, since they are specific to my design. Np=0.9 only under the conditions set out in the impeller tested, likewise, Nq, the pumping number is specific to a design. Most impellers are about 65 percent lower than my design.
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