Thrust efficient turbofan engine

Patent metadata

Field	Value
Publication number	US-10047699-B2
Application number	US-201715450455-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 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.

First claim

What is claimed is:

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 and less than 26 fan blades;
a low speed spool having an inner shaft and a power turbine;
a high speed 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 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 that is less than 0.25 at a sea level takeoff power 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, 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 is less than 0.20 at the sea level takeoff power condition.

3. The turbofan engine as recited in claim 2 , wherein the EUTP is less than 0.15 at the sea level takeoff power 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.

5. The turbofan engine as recited in claim 4 , wherein, the power turbine has 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 1150 ft/sec in operation and further comprising a two-stage high pressure turbine.

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 , 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.

11. 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”) 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 0.15 at a cruise condition, and less than 0.25 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 6,200 rpm and 12,500 rpm.

12. The turbofan engine as recited in claim 11 , wherein the EUTP is less than 0.125 for at least one of a climb condition and the cruise condition.

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

14. The turbofan engine as recited in claim 13 , wherein the EUTP at the sea level takeoff power condition is less than 0.15.

15. The turbofan engine as recited in claim 14 , 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.

16. The turbofan engine as recited in claim 15 , 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.

17. The turbofan engine as recited in claim 16 , further comprising a bypass ratio greater than 10 in operation, and wherein the EUTP at the climb condition is less than 0.08.

18. The turbofan engine as recited in claim 17 , wherein the fan rotates at a fan tip speed less than 1150 ft/sec in operation and the fan includes less than 20 fan blades.

19. The turbofan engine as recited in claim 18 , wherein the power turbine rotates at a speed that is between 6200 rpm and 12,500 rpm.

20. The turbofan engine as recited in claim 18 , 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.

21. 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 and less than 26 fan blades;
a low speed spool having an inner shaft and a high speed spool having an outer shaft concentric about the inner shaft;
a power turbine part of the low spool 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”) 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 0.15 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 6,200 rpm and 12,500 rpm.

22. The turbofan engine as recited in claim 21 , wherein the EUTP is less than 0.10 at the sea level takeoff power condition.

23. The turbofan engine as recited in claim 22 , wherein the EUTP is less than 0.10 at a cruise condition.

24. The turbofan engine as recited in claim 23 , wherein the EUTP at a climb condition is less than 0.08.

25. The turbofan engine as recited in claim 24 , 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.

26. The turbofan engine as recited in claim 25 , further comprising a two-stage high pressure turbine, and wherein the fan includes less than 20 fan blades.

Assignees

• United Technologies Corp

Inventors

• Sabnis Jayant

Classifications

• F04D29/325

  for axial flow fans (blade mountings F04D29/34, blades F04D29/38) · CPC title

• F02C3/107

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

• F02K3/075 Primary

  controlling flow ratio between flows · CPC title

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F02K3/06 Primary

  with front fan · CPC title