Aeronautical propulsion system with improved propulsion efficiency
AssigneeSafran Aircraft Engines
InventorDidier René André ESCURE
Life of this patent
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Abstract
An aeronautical propulsion system includes a drive shaft, a fan shaft, a fan section including a fan rotor that is rotated by the fan shaft and that include blades, and a reduction structure coupling the drive shaft and the fan shaft. The fan rotor has an aerodynamic load parameter greater than or equal to 0.10 and less than or equal to 0.18, and a mechanical load parameter greater than or equal to 20.0×106 rev·m2·min−1 and less than or equal to 32.0×106 rev·m2·min−1. The aerodynamic load and the mechanical load are defined based on the load parameters, a thrust generated by the system, a bypass ratio, a number of blades, an outer and inner radius of the rotor, a redline speed, and a surface area of the flow stream at the inlet of the fan rotor.
Claims20
An aeronautical propulsion system comprising:
- a drive shaft rotatable about an axis of rotation;
- a fan shaft;
- a fan section comprising a ducted fan rotor rotated by the fan shaft, the fan rotor comprising a plurality of blades;
- a reduction structure that couples the drive shaft and the fan shaft in order to drive the fan shaft at a rotation speed less than the rotation speed of the drive shaft;
- the propulsion system being configured such that the fan rotor has an aerodynamic load parameter greater than or equal to 0.10 and less than or equal to 0.18, and a mechanical load parameter greater than or equal to 20.0×106 rev·m2·min−1 and less than or equal to 32.0×106 rev·m2·min−1,
- where the aerodynamic load and the mechanical load are defined by the following formulas:
- k
- aero
- =
- F
- *
- (
- FN
- *
- BPR
- 0.2
- 1
-
- 0
-
- 0
-
- 0
- )
- 1.35
- n
- ×
- (
- ω
- *
- π
- 3
-
- 0
- )
- 2
- 4
- ×
- (
- R
- e
- 4
- -
- R
- i
- 4
- )
- *
- (
- R
- e
- -
- R
- i
- )
- k
- meca
- =
- ω
- 2
- ×
- S
- and where:
- kaero is the aerodynamic load parameter;
- kmeca is the mechanical load parameter;
- FN is a thrust generated by the propulsion system when the propulsion system is stationary, in take-off speed, in a standard atmosphere and at sea level and is expressed in newtons;
- BPR is a bypass ratio of the propulsion system and is measured when the propulsion system is stationary, in take-off speed, in a standard atmosphere and at sea level;
- n is an number of blades in the fan rotor;
- F
- =
- 39.7
- N
- -
- 1.35
- ·
- (
- rev
- /
- min
- )
- -
- 2
- ·
- m
- -
- 5
- ;
- Re is an outer radius of the fan rotor and corresponds to a distance between the axis of rotation and a point of intersection between a tip and a leading edge of the blades of the fan rotor, and is expressed in meters;
- Ri is an inner radius of the fan rotor and corresponds to a distance between the axis of rotation and a point of intersection between the leading edge of the blades of the fan rotor and a surface of the fan rotor which radially inwardly delimits a flow stream in the fan rotor and is expressed in meters;
- ω is a redline speed of the fan rotor and is expressed in revolutions per minute;
- and
- S is a surface area of the flow stream at the inlet of the fan rotor, which is equal to π×(Re2−Ri2) and is expressed in square metres.
A method for operating a propulsion system comprising a reduction structure that couples a drive shaft and a ducted fan rotor in order to drive the fan rotor at a speed less than a speed of the drive shaft, wherein the fan rotor has an aerodynamic load parameter greater than or equal to 0.10 and less than or equal to 0.18 and a mechanical load parameter greater than or equal to 20.0×106 rev·m2·min−1 and less than or equal to 32.0×106 rev·m2·min−1,
- where the aerodynamic load and the mechanical load are defined by the following formulas:
- k
- aero
- =
- F
- *
- (
- FN
- *
- BPR
- 0.2
- 1
-
- 0
-
- 0
-
- 0
- )
- 1.35
- n
- ×
- (
- ω
- *
- π
- 3
-
- 0
- )
- 2
- 4
- ×
- (
- R
- e
- 4
- -
- R
- i
- 4
- )
- *
- (
- R
- e
- -
- R
- i
- )
- k
- meca
- =
- ω
- 2
- ×
- S
- and where:
- kaero is the aerodynamic load parameter;
- kmeca is the mechanical load parameter;
- FN is the thrust generated by the propulsion system when the propulsion system is stationary, in take-off speed, in a standard atmosphere and at sea level and is expressed in newtons;
- BPR is a bypass ratio of the propulsion system and is measured when the propulsion system is stationary, in take-off speed, in a standard atmosphere and at sea level;
- n is a number of blades in the fan rotor;
- F
- =
- 39.7
- N
- -
- 1.35
- ·
- (
- rev
- /
- min
- )
- -
- 2
- ·
- m
- -
- 5
- .
- Re is an outer radius of the fan rotor and corresponds to a distance between the axis of rotation and a point of intersection between a tip and a leading edge of the blades of the fan rotor, and is expressed in meters;
- Ri is an inner radius of the fan rotor and corresponds to a distance between the axis of rotation and a point of intersection between the leading edge of the blades of the fan rotor and a surface of the fan rotor which radially inwardly delimits a flow stream in the fan rotor and is expressed in meters;
- ω is a redline speed of the fan rotor and is expressed in revolutions per minute;
- and
- S is an surface area of the flow stream at the inlet of the fan rotor, which is equal to π×(Re2−Ri2) and is expressed in square meters.
A method for manufacturing an aeronautical propulsion system comprising:
- dimensioning a propulsion system comprising a reduction structure that couples a drive shaft and a ducted fan rotor in order to drive the fan rotor at a speed less than a speed of the drive shaft, wherein the fan rotor has an aerodynamic load parameter greater than or equal to 0.10 and less than or equal to 0.18 and a mechanical load parameter greater than or equal to 20.0×106 rev·m2·min−1 and less than or equal to 32.0×106 rev·m2·min−1,
- where the aerodynamic load and the mechanical load are defined by the following formulas:
- k
- aero
- =
- F
- *
- (
- FN
- *
- BPR
- 0.2
- 1
-
- 0
-
- 0
-
- 0
- )
- 1.35
- n
- ×
- (
- ω
- *
- π
- 3
-
- 0
- )
- 2
- 4
- ×
- (
- R
- e
- 4
- -
- R
- i
- 4
- )
- *
- (
- R
- e
- -
- R
- i
- )
- k
- meca
- =
- ω
- 2
- ×
- S
- and where:
- kaero is the aerodynamic load parameter;
- kmeca is the mechanical load parameter;
- FN is the thrust generated by the propulsion system when the propulsion system is stationary, in take-off speed, in a standard atmosphere and at sea level and is expressed in newtons;
- BPR is a bypass ratio of the propulsion system and is measured when the propulsion system is stationary, in take-off speed, in a standard atmosphere and at sea level;
- n is a number of blades in the fan rotor;
- F
- =
- 39.7
- N
- -
- 1.35
- ·
- (
- rev
- /
- min
- )
- -
- 2
- ·
- m
- -
- 5
- ;
- Re is an outer radius of the fan rotor and corresponds to a distance between the axis of rotation and a point of intersection between a tip and a leading edge of the blades of the fan rotor, and is expressed in meters;
- Ri is an inner radius of the fan rotor and corresponds to a distance between the axis of rotation and a point of intersection between the leading edge of the blades of the fan rotor and a surface of the fan rotor which radially inwardly delimits a flow stream in the fan rotor and is expressed in meters;
- ω is a redline speed of the fan rotor and is expressed in revolutions per minute;
- and
- S is an surface area of the flow stream at the inlet of the fan rotor, which is equal to π×(Re2−Ri2) and is expressed in square meters;
- and
- manufacturing the propulsion system.
Dependencies are inferred from the claim text.