Thrust efficient turbofan engine

Patent metadata

Field	Value
Publication number	US-10047701-B2
Application number	US-201715450517-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 propulsor section including a fan and a core flow path portion, the fan including less than 20 fan blades and having a fan tip diameter greater than 50 inches and less than 160 inches;
a power turbine; 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 in operation is less than 0.25 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 6,200 rpm and 12,500 rpm.

2. The turbofan engine as recited in claim 1 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.20.

3. The turbofan engine as recited in claim 2 , wherein the EUTP in operation at one of a climb condition and a cruise condition is less than 0.15.

4. The turbofan engine as recited in claim 3 , further comprising a low fan pressure ratio across the fan alone that is less than 1.45 in operation, wherein a ratio between the number of fan blades and a number of rotors in the power turbine is between 3.3 and 8.6.

5. The turbofan engine as recited in claim 4 , wherein the EUTP in operation at one of a climb condition and a cruise condition is less than 0.10.

6. The turbofan engine as recited in claim 5 , wherein the EUTP at the climb condition is less than 0.08.

7. The turbofan engine as recited in claim 6 , further comprising a gas generator section, the gas generation section including the core flow path portion of the propulsor section, a low pressure compressor, a high pressure compressor, a combustor, a two-stage high pressure turbine, and a part of the power turbine, the gas generator having an overall pressure ratio between entering airflow into the gas generator and exiting gas stream from the gas generator that is between 40 and 80 in operation.

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

9. The turbofan engine as recited in claim 2 , wherein a ratio between the number of fan blades and a number of rotors in the power turbine is between 3.3 and 8.6, and the EUTP at the maximum takeoff thrust is less than 0.15.

10. The turbofan engine as recited in claim 9 , wherein the EUTP at the maximum takeoff thrust is less than 0.10.

11. The turbofan engine as recited in claim 2 , wherein the fan rotates in operation at a fan tip speed less than 1150 ft/sec.

12. The turbofan engine as recited in claim 11 , wherein the EUTP in operation at the maximum takeoff thrust is less than 0.25 and the power turbine has a pressure ratio greater than 5 measured prior to an inlet to the power turbine as related to a pressure measured at an outlet of the power turbine prior to any exhaust nozzle.

13. The turbofan engine as recited in claim 12 , wherein the EUTP in operation at a climb condition is less than 0.08.

14. The turbofan engine as recited in claim 12 , wherein the EUTP in operation at a cruise condition is less than 0.05.

15. The turbofan engine as recited in claim 12 , further comprising a low fan pressure ratio across the fan alone that is less than 1.45 in operation.

16. The turbofan engine as recited in claim 11 , wherein the EUTP in operation at a cruise condition is less than 0.10.

17. The turbofan engine as recited in claim 16 , wherein the EUTP at the maximum takeoff thrust is less than 0.20.

18. The turbofan engine as recited in claim 16 , wherein the EUTP at the maximum takeoff thrust is less than 0.15.

19. The turbofan engine as recited in claim 16 , wherein the EUTP at the maximum takeoff thrust is less than 0.10.

20. A turbofan engine comprising:
a propulsor section including a fan having a fan tip diameter greater between 50 inches and 160 inches;
a power turbine, 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; and
a speed reduction device in driving connection between the power turbine and the fan, wherein the speed reduction device includes a speed reduction of 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 in operation is less than 0.20 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 first rotational speed is between 6200 rpm and 12500 rpm.

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

22. The turbofan engine as recited in claim 21 , wherein the EUTP in operation at one of a climb condition and a cruise condition is less than 0.10.

23. The turbofan engine as recited in claim 22 , further comprising a low fan pressure ration across the fan alone that is less than 1.45 in operation.

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

25. The turbofan engine as recited in claim 20 , wherein the EUTP in operation at a cruise condition is less than 0.08, and the EUTP in operation at the sea level takeoff power condition is less than 0.15.

26. The turbofan engine as recited in claim 20 , further comprising a gas generator section, the gas generation section including the core flow path portion of the propulsor section, a low pressure compressor, a high pressure compressor, a combustor, a two-stage high pressure turbine, and a part of the power turbine, the gas generator having an overall pressure ratio between entering airflow into the gas generator and exiting gas stream from the gas generator that is between 40 and 80 in operation, wherein the EUTP in operation at the sea level takeoff power condition is less than 0.15.

Assignees

• United Technologies Corp

Inventors

• Sabnis Jayant

Classifications

• F02K3/06 Primary

  with front fan · CPC title

• F02C3/107

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

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F02K1/52

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

• F05D2240/35

  Combustors or associated equipment · CPC title