Patent ID: 9051877
Filing Date: 2015-06-09
Classification: F02C,F02K,F05D

Abstract:
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 first speed reduction device driven by the power turbine; a second speed reduction device driven by the power turbine, wherein the power turbine section includes an inner shaft supporting a first plurality of airfoils rotatable in a first direction and a drum including a second plurality of airfoils and driven by the second speed reduction device in a direction opposite the first plurality of airfoils; and a propulsor section including a fan driven by the power turbine through the first speed reduction device at a second speed lower than the first rotational speed for generating propulsive thrust as a mass flow rate of air through a bypass flow path, wherein 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 0.15 at a take-off condition.