ref Reeds Motor Engineering Knowledge for Marine Engineers, vol 12, chapter 1, page 3
Specific Fuel Consumption
Fuel consumption per unit energy at the cylider or output shaft, kg/kWh (or kg/kWs). 0.21 kg/kWh would be normal on a shaft energy basis for the engine only and 0.235 kg?kWh all purpose (i.e. including auxiliaries)
As BP says, slip is calculated by dividing the actual distance run by the theoretical distance, obtained by multiplying the prop pitch by the number of revolutions in a given time. Slip is not relevant to controllable pitch propellors.
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