Performance coefficient

The performance coefficient (λ) is a characteristic coefficient identifying the pump input power.
The following equations are yielded in conjunction with the pump power output (PQ) and pump input power (P):

ρ    Density of fluid handled
η    Pump efficiency
U2   Circumferential velocity at the impeller outlet
D2   Impeller diameter at the outlet
b2   Impeller outlet width
φ    Flow coefficient
ψ    Head coefficient

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