ClueLuma

Flow versus speed calculator

For similar centrifugal operation, flow follows shaft speed.

Units
Q2=Q1×N2N1Q_{2} = \frac{Q_{1} \times N_{2}}{N_{1}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

CFM or GPM
rpm
rpm
CFM or GPM

Worked example

Given

  • Q1Q_{1} = 9,000 CFM or GPM
  • N2N_{2} = 1,400 rpm
  • N1N_{1} = 1,750 rpm
Q2=9000×14001750=7,200Q_{2} = \frac{9000 \times 1400}{1750} = 7{,}200

Symbols and units

SymbolMeaningUnit
Q2Q_{2}new flowCFM or GPM
Q1Q_{1}initial flowCFM or GPM
N2N_{2}new shaft speedrpm
N1N_{1}initial shaft speedrpm

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Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.