In flight mechanics, the “specific fuel consumption” (SFC) of a turbofan engine refers to the rate at which the engine consumes fuel to produce a certain amount of thrust or power. It is a critical parameter used to evaluate the efficiency and fuel economy of a turbofan engine.
Specific fuel consumption is typically expressed as the amount of fuel (in mass) consumed per unit of thrust or power produced by the engine. The most common units are pounds of fuel per pound of thrust (lb/lbf) or kilograms of fuel per kilowatt-hour (kg/kWh) of mechanical power.
The specific fuel consumption can be calculated using the following equation:
SFC = Fuel Flow Rate / Thrust or Power Output
where: SFC = Specific Fuel Consumption (mass of fuel per unit of thrust or power) Fuel Flow Rate = Rate at which fuel is consumed by the engine (mass per unit time) Thrust or Power Output = Thrust generated by the engine or mechanical power produced (force or power per unit time)