Hull Efficiency η_H

η_H = (1 − t) / (1 − w). Usually 1.05–1.15 for single-screw full-form hulls - the wake gain outweighs thrust deduction.

propulsion

Thrust deduction t - Wake fraction w -

Hull efficiency η_H: 1.171 -

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\eta_H = \frac{1 - t}{1 - w}

Symbol	Meaning	Unit
$t$	Thrust deduction fraction
$w$	Taylor wake fraction
$\eta_H$	Hull efficiency

Source: Harvald - Resistance and Propulsion of Ships

In short

\u03b7_H = (1 \u2212 t) / (1 \u2212 w).

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