Thrust efficient turbofan engine
AssigneeUntied Technologies Corporation
InventorJayant Sabnis
Life of this patent
Estimating the term…
Abstract
A disclosed turbofan engine includes a gas generator section for generating a gas stream flow. 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 forty-five (45) 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 for cruise, climb and sea level takeoff power conditions.
Claims28
A turbofan engine comprising:
- a propulsor section, the propulsor section having a fan and a core flow path portion, the fan having a number of fan blades that have a fan tip diameter greater than 50 inches and less than 160 inches;
- a low spool having an inner shaft and a power turbine including from three to six rotors, wherein a ratio between the number of fan blades and a number of power turbine rotors is between 3.3 and 8.6;
- a high spool having an outer shaft concentric about the inner shaft;
- a geared architecture in driving connection between the power turbine and the fan, wherein the geared architecture has a gear ratio greater than 2.3;
- and
- an Engine Unit Thrust Parameter (“EUTP”) defined as net engine thrust divided by a product of the mass flow rate of air through a bypass flow path, the fan tip diameter of the fan and a first rotational speed of the power turbine, the EUTP is less than 0.30 in operation at a maximum takeoff thrust;
- wherein the turbofan engine is capable of generating a propulsive thrust between 16,000 lbf and about 120,000 lbf, the mass flow rate of air through the bypass flow path is between 625 Ibm/sec and 80,000 Ibm/sec and the first rotational speed is between 6,200 rpm and 12,500 rpm.
A turbofan engine comprising:
- a power turbine including from three to six rotors;
- a geared architecture in driving connection between the power turbine and a fan, wherein the geared architecture has a gear ratio greater than 2.3;
- a propulsor section, the propulsor section having the fan and a core flow path portion, the fan having a fan tip diameter between 45 inches and 160 inches;
- and
- a low fan pressure ratio across the fan alone that is less than 1.45 in operation;
- wherein an Engine Unit Thrust Parameter (“EUTP”) is defined as net engine thrust divided by a product of the mass flow rate of air through a bypass flow path, the fan tip diameter of the fan and a first rotational speed of the power turbine and in operation is less than 0.30 at a sea level takeoff power condition, wherein the net engine thrust is between 16,000 lbf and 120,000 lbf, the mass flow rate of air through the bypass flow path is between 625 Ibm/sec and 80,000 Ibm/sec and the first rotational speed is between 6,200 rpm and 12,500 rpm.
Dependencies are inferred from the claim text.