Quasi-Propulsive Coefficient η_D

Quasi-propulsive coefficient η_D = η_H × η_O × η_R - the ratio between effective power (EHP) and delivered power (DHP).

QPCPropellerEfficiency

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Formula, assumptions, and limits

\eta_D = \eta_H \eta_O \eta_R = \frac{1-t}{1-w} \eta_O \eta_R

Symbol	Meaning	Unit
$t$	Thrust deduction
$w$	Wake fraction
$\eta_O$	Open-water efficiency
$\eta_R$	Relative rotative efficiency

Source: Rawson & Tupper Vol 2

Quasi-propulsive coefficient \u03b7_D = \u03b7_H \u00d7 \u03b7_O \u00d7 \u03b7_R - the ratio between effective power (EHP) and delivered power (DHP).