Thrust efficient turbofan engine

Patent metadata

Field	Value
Publication number	US-10047702-B2
Application number	US-201715450599-A
Country	US
Kind code	B2
Filing date	Mar 6, 2017
Priority date	Mar 15, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

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 take-off power conditions.

First claim

What is claimed is:

1. A turbofan engine comprising:
a low spool having an inner shaft and a power turbine including between 3 and 6 stages;
a high spool having an outer shaft concentric about the inner shaft;
a propulsor section including a fan with a number of fan blades that have a fan tip diameter between 50 inches and 160 inches, wherein a ratio between the number of fan blades and a number of power turbine rotors is between 3.3 and 8.6; and
a speed reduction device in driving connection between the power turbine and the fan, wherein the speed reduction device includes a speed reduction greater than 2.3, wherein 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, a tip diameter of a 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 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 lbm/sec and 80,000 lbm/sec and the first rotational speed is between 6200 rpm and 12,500 rpm.

2. The turbofan engine as recited in claim 1 , wherein the EUTP in operation at the maximum take-off thrust is less than 0.25.

3. The turbofan engine as recited in claim 2 , wherein the EUTP in operation at a cruise condition is less than 0.10.

4. The turbofan engine as recited in claim 3 , wherein the EUTP in operation at a climb condition is less than 0.10.

5. The turbofan engine as recited in claim 4 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.10.

6. The turbofan engine as recited in claim 4 , wherein the EUTP in operation at a cruise condition is less than 0.08.

7. The turbofan engine as recited in claim 6 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.10.

8. The turbofan engine as recited in claim 1 , further comprising a low fan pressure ratio across the fan alone that is less than 1.45 in operation.

9. The turbofan engine as recited in claim 8 , further comprising a gas generator section including a core flow path portion of the propulsor section, a low pressure compressor, a combustor, a two-stage high pressure turbine and a part of the power turbine.

10. The turbofan engine as recited in claim 9 , wherein the number of fan blades is less than 20.

11. The turbofan engine as recited in claim 10 , wherein the EUTP at the maximum takeoff thrust is less than 0.15.

12. The turbofan engine as recited in claim 11 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.10.

13. The turbofan engine as recited in claim 1 , wherein the fan rotates in operation at a fan tip speed less than about 1150 ft/sec.

14. The turbofan engine as recited in claim 13 , further comprising a gas generator section including a core flow path portion of the propulsor section, a low pressure compressor, a high pressure compressor, a combustor, a high pressure turbine, and a part of the power turbine, the gas generator in operation having an overall pressure ratio between entering airflow into the gas generator and a gas stream exiting from the gas generator that is between 40 and 80.

15. The turbofan engine as recited in claim 14 , wherein the fan includes less than 20 fan blades.

16. The turbofan engine as recited in claim 15 , wherein the gas generator includes a two stage high pressure turbine.

17. The turbofan engine as recited in claim 16 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.25 and at a cruise condition is less than 0.10.

18. The turbofan engine as recited in claim 17 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.10.

19. A turbofan engine comprising:
a propulsor section including a fan having less than 20 fan blades and a fan tip diameter between 50 inches and 160 inches, and that rotates at a fan tip speed less than about 1150 ft/sec in operation;
a low speed spool having an inner shaft and a power turbine including more than 3 stages and no more than 6 stages and rotating at a speed between 6200 rpm and about 12,500 rpm;
a high speed spool having an outer shaft concentric about the inner shaft; and
a speed reduction device in driving connection between the power turbine and the fan, wherein the speed reduction device includes a speed reduction greater than 2.3, wherein an Engine Unit Thrust Parameter (“EUTP”) defined as net engine thrust divided by a product of a mass flow rate of air through a bypass flow path, a tip diameter of the fan and a first rotational speed of the power turbine 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 lbm/sec and 80,000 lbm/sec and the fan tip diameter is between 50 inches and 160 inches.

20. The turbofan engine as recited in claim 19 , wherein the EUTP in operation at the sea level takeoff power condition is less than 0.25.

21. The turbofan engine as recited in claim 20 , wherein high speed spool has a two stage high pressure turbine.

22. The turbofan engine as recited in claim 20 , wherein the EUTP in operation at one of a climb condition and a cruise condition is less than 0.15.

23. The turbofan engine as recited in claim 22 , wherein a ratio between a number of fan blades and a number of rotors in the power turbine is between 3.3 and 8.6.

24. The turbofan engine as recited in claim 23 , wherein the EUTP in operation at one of a climb condition and a cruise condition is less than 0.10.

25. The turbofan engine as recited in claim 24 , further comprising a low fan pressure ratio across the fan alone that is less than 1.45 in operation.

26. The turbofan engine as recited in claim 25 , wherein the EUTP in operation at the sea level takeoff power condition is less than 0.20.

27. The turbofan engine as recited in claim 26 , wherein the EUTP at the sea level takeoff power condition is less than 0.15 and at a cruise condition is less than 0.08.

28. The turbofan engine as recited in claim 27 , further comprising a gas generator section including a core flow path portion of the propulsor section, a low pressure compressor, a high pressure compressor, a combustor, and a part of the power turbine, the gas generator in operation having an overall pressure ratio between entering airflow into the gas generator and a gas stream exiting from the gas generator that is between 40 and 80, wherein a ratio between a number of fan blades and a number of rotors in the power turbine is between about 3.3 and 8.6.

Assignees

• United Technologies Corp

Inventors

• Sabnis Jayant

Classifications

• F02K1/52

  Nozzles specially constructed for positioning adjacent to another nozzle or to a fixed member, e.g. fairing · CPC title

• F01D19/02

  dependent on temperature of component parts, e.g. of turbine-casing · CPC title

• F02C3/107

  with two or more rotors connected by power transmission · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F02K3/06 Primary

  with front fan · CPC title