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US 10,704,415 B2Granted
Gas turbine engine with low fan noise
AssigneeRaytheon Technologies Corporation
InventorsBruce L. Morin, Wesley K. Lord
Life of this patent
Estimating the term…
Abstract
In accordance with one aspect of the disclosure, a gas turbine engine, method of using and designing such is disclosed. The gas turbine engine may comprise a fan including a plurality of blades, and a variable area fan nozzle. The fan may be configured to have a design point fan tip leading edge relative flow angle βADP, and may be further configured to have an off-design point fan tip leading edge relative flow angle β at an off-design fan operating point. The variable area fan nozzle may be configured to manipulate the amount of air flowing through the fan so that the absolute value of a difference between the design point fan tip leading edge relative flow angle βADP and the off-design point fan tip leading edge relative flow angle β is in a specified range.
Claims20
A gas turbine engine comprising:
- a fan including a plurality of blades each blade having a leading edge, the fan having a design point fan tip leading edge relative flow angle βADP, and further having an off-design point fan tip leading edge relative flow angle β at an off-design fan operating point, the off-design fan operating point being an acoustic certification point, the acoustic certification point selected from the group consisting of approach, flyover and lateral as defined by Part 36 of the Federal Airworthiness Regulations;
- a variable area fan nozzle configured to manipulate the amount of air flowing through the fan so that the absolute value of a difference between the design point fan tip leading edge relative flow angle βADP and the off-design point fan tip leading edge relative flow angle β is in the range of zero degrees to six degrees,
- wherein the design point fan tip leading edge relative flow angle βADP is defined by the solution to the following set of simultaneous equations
- W
- C
- ,
- ADP
-
- /
-
- A
- =
- 85.38
-
- M
- ADP
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- ADP
- 2
- )
- 3
- and
- β
- ADP
- =
- tan
- -
- 1
- (
- 49.02
-
- M
- ADP
-
- 518.67
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- ADP
- 2
- )
- U
- C
- ,
- ADP
- )
- wherein further, the off-design point tip relative flow angle β is defined by the solution to the following set of simultaneous equations
- W
- C
-
- /
-
- A
- =
- 85.38
-
- M
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- 2
- )
- 3
- and
- β
- =
- tan
- -
- 1
- (
- 49.02
-
- 518.67
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- 2
- )
- U
- C
- )
- wherein (WC,ADP/A) is design point corrected mass flow rate per unit area in pounds mass per second per square foot, (UC,ADP) is design point corrected tip speed in feet per second, MADP is design point airflow Mach number, and βADP is in degrees, (WC/A) is corrected mass flow rate per unit area in pounds mass per second per square foot, UC is corrected tip speed in feet per second, M is airflow Mach number, and β is in degrees.
105 more elements
A method of using a gas turbine propulsion system, the method comprising:
- operating a gas turbine engine including a fan and a variable area fan nozzle, the fan including a plurality of blades each having a leading edge, the fan configured to have a design point fan tip leading edge relative flow angle βADP, and further configured to have an off-design point fan tip leading edge relative flow angle β at an off-design fan operating point, the off-design fan operating point being an acoustic certification point, the acoustic certification point selected from the group consisting of approach, flyover and lateral as defined by Part 36 of the Federal Airworthiness Regulations;
- using the variable area fan nozzle to manipulate the amount of air flowing through the fan so that the absolute value of a difference between the design point fan tip leading edge relative flow angle βADP and the off-design point fan tip leading edge relative flow angle β is in the range of zero degrees to six degrees,
- wherein the design point fan tip leading edge relative flow angle βADP is defined by the solution to the following set of simultaneous equations
- W
- C
- ,
- ADP
-
- /
-
- A
- =
- 85.38
-
- M
- ADP
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- ADP
- 2
- )
- 3
- and
- β
- ADP
- =
- tan
- -
- 1
- (
- 49.02
-
- M
- ADP
-
- 518.67
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- ADP
- 2
- )
- U
- C
- ,
- ADP
- )
- wherein further the off-design point tip relative flow angle β is defined by the solution to the following set of simultaneous equations
- W
- C
-
- /
-
- A
- =
- 85.38
-
- M
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- 2
- )
- 3
- and
- β
- =
- tan
- -
- 1
- (
- 49.02
-
- 518.67
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- 2
- )
- U
- C
- )
- wherein (WC,ADP/A) is design point corrected mass flow rate per unit area in pounds mass per second per square foot, (UC,ADP) is design point corrected tip speed in feet per second, MADP is design point airflow Mach number, and βADP is in degrees, (WC/A) is corrected mass flow rate per unit area in pounds mass per second per square foot, UC is corrected tip speed in feet per second, M is airflow Mach number, and β is in degrees.
105 more elements
A gas turbine engine comprising:
- a fan including a plurality of blades each blade having a leading edge, the fan having a design point fan tip leading edge relative flow angle βADP, and further having an off-design point fan tip leading edge relative flow angle β at an off-design fan operating point, the off-design fan operating point being an acoustic certification point, the acoustic certification point selected from the group consisting of approach, flyover and lateral as defined by Part 36 of the Federal Airworthiness Regulations;
- a variable area fan nozzle configured to manipulate the amount of air flowing through the fan so that the absolute value of a difference between the design point fan tip leading edge relative flow angle βADP and the off-design point fan tip leading edge relative flow angle β is less than five degrees,
- wherein the design point fan tip leading edge relative flow angle βADP is defined by the solution to the following set of simultaneous equations
- W
- C
- ,
- ADP
-
- /
-
- A
- =
- 85.38
-
- M
- ADP
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- ADP
- 2
- )
- 3
- and
- β
- ADP
- =
- tan
- -
- 1
- (
- 49.02
-
- M
- ADP
-
- 518.67
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- ADP
- 2
- )
- U
- C
- ,
- ADP
- )
- wherein further, the off-design point tip relative flow angle β is defined by the solution to the following set of simultaneous equations
- W
- C
-
- /
-
- A
- =
- 85.38
-
- M
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- 2
- )
- 3
- and
- β
- =
- tan
- -
- 1
- (
- 49.02
-
- 518.67
-
- /
-
- (
- 1
- +
- 0.2
-
- M
- 2
- )
- U
- C
- )
- wherein (WC,ADP/A) is design point corrected mass flow rate per unit area in pounds mass per second per square foot, (UC,ADP) is design point corrected tip speed in feet per second, MADP is design point airflow Mach number, and βADP is in degrees, (WC/A) is corrected mass flow rate per unit area in pounds mass per second per square foot, UC is corrected tip speed in feet per second, M is airflow Mach number, and β is in degrees.
105 more elements
Dependencies are inferred from the claim text.