HomeCalculatorsWake Fraction (Harvald 1983)

Wake Fraction (Harvald 1983)

Closed-form Harvald estimate of the Taylor wake fraction w from block coefficient - single- and twin-screw variants.

Propulsion
Wake fraction w
0.360 -
Thrust deduction t
0.226 -
Formula, assumptions, and limits

Simple Harvald 1983 closed-form; for fine hulls with bulbous stern the model-basin result is lower (10–15 %). Thrust deduction t is correlated to w via Harvald's second curve: t ≈ 0.60 w + 0.01.

Symbol legend

SymbolMeaningUnitSource
Block coefficient - hydrostatic table
Taylor wake fraction - result
Thrust deduction (correlated) - result