Thrust efficient turbofan engine

摘要

A turbofan engine according to an exemplary embodiment of this disclosure, among other possible things includes a gas generator section for generating a gas stream flow with higher energy per unit mass flow than that contained in ambient air. A power turbine converts the gas stream flow into shaft power. The power turbine rotates at a first rotational speed. A speed reduction device is driven by the power turbine. A propulsor section includes a fan driven by the power turbine through the speed reduction device at a second speed lower than the first speed for generating propulsive thrust as a mass flow rate of air through a bypass flow path. The fan includes a tip diameter greater than about fifty (50) inches and an Engine Unit Thrust Parameter (“EUTP”) defined as net engine thrust divided by a product of the mass flow rate of air through the bypass flow path, a tip diameter of the fan and the first rotational speed of the power turbine is less than about 0.30 at a take-off condition.

主权项

1. A turbofan engine comprising:
a gas generator section for generating a gas stream flow with higher energy per unit mass flow than that contained in ambient air; a power turbine converting the gas stream flow into shaft power, the power turbine rotating at a first rotational speed; a speed reduction device driven by the power turbine; and a propulsor section including a fan driven by the power turbine through the speed reduction device at a second speed lower than the first speed for generating propulsive thrust as a mass flow rate of air through a bypass flow path, wherein the fan includes a tip diameter greater than about fifty (50) inches and an Engine Unit Thrust Parameter (“EUTP”) defined as net engine thrust divided by a product of the mass flow rate of air through the bypass flow path, a tip diameter of the fan and the first rotational speed of the power turbine is less than about 0.30 at a take-off condition.