Efficient, low pressure ratio propulsor for gas turbine engines

Patent metadata

Field	Value
Publication number	US-9506422-B2
Application number	US-201113176365-A
Country	US
Kind code	B2
Filing date	Jul 5, 2011
Priority date	Jul 5, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A gas turbine engine includes a spool, a turbine coupled to drive the spool, and a propulsor that is coupled to be driven by the turbine through the spool. A gear assembly is coupled between the propulsor and the spool such that rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extends from the hub. The row includes no more than 20 of the propulsor blades.

First claim

What is claimed is:

1. A gas turbine engine comprising:
a spool;
a turbine coupled to drive the spool;
a propulsor coupled to be driven by said turbine through said spool, said propulsor being located at an inlet of a core flow passage and bypass flow passage having a design pressure ratio that is between 1.3 and 1.4, with regard to an inlet pressure and an outlet pressure of said bypass flow passage, at a design rotational speed of the propulsor, said bypass flow passage defining a bypass ratio of 8.5 to 13.5 with regard to flow through said bypass flow passage and flow through said core flow passage; and
a gear assembly coupled between said propulsor and said spool such that rotation of said spool drives said propulsor at a lower speed than said spool, said propulsor being susceptible at said lower speed to propulsive losses from at least one of flow discontinuities, shocks and turbulence,
wherein said propulsor includes a hub and a row of propulsor blades that extend from said hub, and said row includes a number (N) of said propulsor blades that is no more than 20, and
wherein each of said propulsor blades extends radially between a root and a tip and in a chord direction between a leading edge and a trailing edge at the tip to define a chord dimension (CD), said row of propulsor blades defining a circumferential pitch (CP) with regard to said tips, said row of propulsor blades including a solidity value (R) of CD/CP that is between 1.0 and 1.3 and a ratio of N/R from 9 to 20 to manage said propulsive losses at said lower speed.

2. The gas turbine engine as recited in claim 1 , wherein R is from 1.1 to 1.2.

3. The gas turbine engine as recited in claim 1 , further comprising a low pressure compressor section and a low pressure turbine section that are each coupled to be driven through said spool, and a high pressure compressor section and a high pressure turbine section that are coupled to be driven through another spool.

4. The gas turbine engine as recited in claim 1 , wherein a ratio of N/R is from 9 to 14.

5. The gas turbine engine as recited in claim 1 , wherein the ratio of N/R is 9 to 15.

6. The gas turbine engine as recited in claim 1 , including a variable area nozzle operative to change a cross-sectional area of an outlet of said bypass flow passage.

7. The gas turbine engine as recited in claim 1 , wherein the number (N) is a total number of said propulsor blades, said total number being between 12 and 20 and said propulsor blades all being equally circumferentially spaced.

8. The gas turbine engine as recited in claim 1 , wherein said number (N) of said propulsor blades, said solidity value (R), and said ratio of N/R are in a combination selected from the Table:

Number of Blades (N)
Solidity
Ratio N/R

20
1.3
15.4

18
1.3
13.8

16
1.3
12.3

14
1.3
10.8

12
1.3
 9.2

20
1.2
16.7

18
1.2
15.0

16
1.2
13.3

14
1.2
11.7

12
1.2
10.0

20
1.1
18.2

18
1.1
16.4

16
1.1
14.5

14
1.1
12.7

12
1.1
10.9

20
1.0
20.0

18
1.0
18.0

16
1.0
16.0

14
1.0
14.0

12
1.0
 12.0.

9. The gas turbine engine as recited in claim 8 , wherein the number (N) of said blades is 20.

10. The gas turbine engine as recited in claim 8 , wherein the number (N) of said blades is 18.

11. The gas turbine engine as recited in claim 8 , wherein the number (N) of said blades is 16, 18, or 20.

Assignees

• Gallagher Edward J
• Monzon Byron R
• United Technologies Corp

Inventors

• Gallagher Edward J
• Monzon Byron R

Classifications

• F02K1/06

  Varying effective area of jet pipe or nozzle (by using fluid jets to influence the jet flow F02K1/30) · CPC title

• F02K3/06 Primary

  with front fan · CPC title

• F05D2260/4031

  as in toothed gearing · CPC title

• F05D2220/327

  to drive shrouded, high solidity propeller · CPC title

• F01D17/14

  varying effective cross-sectional area of nozzles or guide conduits · CPC title