THRUST EFFICIENT TURBOFAN ENGINE

• US 20170175675A1
• Filed: 03/06/2017
• Published: 06/22/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Sabnis, Jayant
• Granted Patent: US 10,047,699 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 27/10 of gas-turbine type jet aircraft B64D27/16
• CPC Class Codes: F01D 15/12 Combinations with mechanical gearing driven by multiple engines F01D13/00
• CPC Class Codes: F01D 19/02 dependent on temperature of component parts, e.g. of turbine-casing
• CPC Class Codes: F01D 5/06 Rotors for more than one axial stage, e.g. of drum or multiple disc type; Details thereof, e.g. shafts, shaft connections F01D5/022, F01D5/023 take precedence
• CPC Class Codes: F02C 3/04 having a turbine driving a compressor power transmission arrangements F02C7/36; control of working fluid flow F02C9/16
• CPC Class Codes: F02C 3/107 with two or more rotors connected by power transmission
• CPC Class Codes: F02K 1/52 Nozzles specially constructed for positioning adjacent to another nozzle or to a fixed member, e.g. fairing
• CPC Class Codes: F02K 3/06 with front fan
• CPC Class Codes: F02K 3/075 controlling flow ratio between flows
• CPC Class Codes: F04D 19/02 Multi-stage pumps
• CPC Class Codes: F04D 29/325 for axial flow fans blade mountings F04D29/34, blades F04D29/38
• CPC Class Codes: F05D 2220/323 for aircraft propulsion, e.g. jet engines
• CPC Class Codes: F05D 2220/36 specially adapted for the fan of turbofan engines
• CPC Class Codes: F05D 2240/35 Combustors or associated equipment

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 about 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 take-off power conditions.

Claims

1. A turbofan engine comprising:

a propulsor section including a fan, wherein the fan includes a fan tip diameter greater than 50 inches and less than 160 inches;

a power turbine;

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”

) in operation that is less than 0.25 at a take-off condition, wherein a mass flow generated through a bypass passage by the propulsor section is between about 625 lbm/sec and about 80,000 lbm/sec.

2. The turbofan engine as recited in claim 1, wherein the EUTP is less than about 0.20 at the take-take off condition.

3. The turbofan engine as recited in claim 2, wherein the EUTP is less than about 0.15 at the take-off condition.

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, and a bypass ratio greater than 10 in operation.

5. The turbofan engine as recited in claim 4, further comprising a two-stage high pressure turbine, and the power turbine having a plurality of stages, wherein a ratio between the number of fan blades and the number of stages in the power turbine is between 3.3 and 8.6.

6. The turbofan engine as recited in claim 5, wherein the fan rotates at a fan tip speed less than about 1150 ft/sec in operation.

7. The turbofan engine as recited in claim 6, wherein the fan includes less than 20 fan blades.

8. The turbofan engine as recited in claim 7, wherein the EUTP at a cruise condition is less than 0.10.

9. The turbofan engine as recited in claim 8, wherein the EUTP at a climb condition is less than 0.08.

10. The turbofan engine as recited in claim 5, wherein the power turbine rotates at a speed in operation that is between 6200 rpm and about 12,500 rpm, and the turbofan engine is capable of generating a propulsive thrust in operation that is between 16,000 lbf and about 120,000 lbf.

11. The turbofan engine as recited in claim 5, 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, the 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.

12. A turbofan engine comprising:

a propulsor section including a fan, wherein the fan includes a fan tip diameter greater than 50 inches and less than 160 inches;

a power turbine having a plurality of stages; and

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;

wherein an Engine Unit Thrust Parameter (“

EUTP”

) in operation is less than 0.15 at a cruise condition, and less than 0.25 at a take-off condition.

13. The turbofan engine as recited in claim 12, wherein the EUTP is less than 0.125 for at least one of a climb condition and the cruise condition.

14. The turbofan engine as recited in claim 13, wherein the EUTP at the cruise condition is less than 0.08.

15. The turbofan engine as recited in claim 14, wherein the EUTP at a take-off condition is less than 0.15.

16. The turbofan engine as recited in claim 15, wherein mass flow generated by the propulsor section through a bypass passage during operation is between about 625 lbm/sec and about 80,000 lbm/sec, and the turbofan engine generates a propulsive thrust during operation that is between 16,000 lbf and about 120,000 lbf.

17. The turbofan engine as recited in claim 16, wherein a ratio between the number of fan blades and the number of stages in the power turbine is between 3.3 and 8.6.

18. The turbofan engine as recited in claim 17, further comprising a two-stage high pressure turbine and a low fan pressure ratio across the fan alone that is less than 1.45 in operation.

19. The turbofan engine as recited in claim 18, further comprising a bypass ratio greater than 10 in operation, and wherein the EUTP at the climb condition is less than 0.08.

20. The turbofan engine as recited in claim 19, wherein the fan rotates at a fan tip speed less than about 1150 ft/sec in operation and the fan includes less than 20 fan blades.

21. The turbofan engine as recited in claim 20, wherein the power turbine rotates at a speed that is between 6200 rpm and about 12,500 rpm.

22. The turbofan engine as recited in claim 21, 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, the 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.

23. A turbofan engine comprising:

a propulsor section including a fan and a low fan pressure ratio across the fan alone that is less than 1.45 in operation, wherein the fan includes a fan tip diameter greater than 50 inches and less than 160 inches;

a power turbine rotating including from three (3) to six (6) stages;

a geared architecture in driving connection between the power turbine and the fan, wherein an Engine Unit Thrust Parameter (“

EUTP”

) in operation is less than 0.15 at a take-off condition.

24. The turbofan engine as recited in claim 23, wherein the EUTP is less than 0.10 at the take-off condition.

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

26. The turbofan engine as recited in claim 25, wherein the EUTP at a climb condition is less than 0.08.

27. The turbofan engine as recited in claim 26, further comprising a bypass ratio greater than ten (10) in operation at the maximum take-off power condition.

28. The turbofan engine as recited in claim 27, wherein mass flow generated by the propulsor section through a bypass flow path during operation is between about 625 lbm/sec and about 80,000 lbm/sec, and the turbofan engine generates a propulsive thrust during operation that is between 16,000 lbf and about 120,000 lbf.

29. The turbofan engine as recited in claim 28, wherein a ratio between the number of fan blades and the number of rotors in the power turbine is between about 3.3 and about 8.6.

30. The turbofan engine as recited in claim 29, further comprising a two-stage high pressure turbine, and wherein the fan includes less than 20 fan blades.