Aeronautical propulsion system comprising an optimized fan section
AssigneeSafran Aircraft Engines
InventorsMatthieu Pierre Michel Dubosc, Guillaume Olivier Vartan Martin, Didier René André Escure
Life of this patent
Estimating the term…
Abstract
A fan section of an aeronautical propulsion system includes a fan rotor including seventeen blades to twenty blades and having a solidity strictly less than 1.0. The solidity is equal to a ratio between a chord at the blade tip and an inter-blade pitch at the blade tip. The fan section has a hub-tip ratio greater than or equal to 0.22 and less than or equal to 0.32, a pressure ratio greater than or equal to 1.05 and less than or equal to 1.5, and a peripheral speed at the blade tip greater than or equal to 260 m/s and less than or equal to 400 m/s. The pressure ratio and the peripheral speed are measured at cruising speed.
Claims16
A propulsion system comprising:
- a drive shaft movable in rotation about an axis of rotation;
- a fan shaft;
- a fan section comprising a fan rotor driven in rotation by the fan shaft;
- and
- a reduction structure coupling the drive shaft and the fan shaft in order to drive the fan shaft at a rotational speed lower than the rotational speed of the drive shaft;
- wherein the fan rotor comprises at least seventeen blades and at most twenty blades and has a solidity strictly less than 1.0, where the solidity is equal to a ratio between a chord at the blade tip and an inter-blade pitch at the blade tip, the fan section having a hub-tip ratio greater than or equal to 0.22 and less than or equal to 0.32, a pressure ratio greater than or equal to 1.05 and less than or equal to 1.5 and a peripheral speed at the blade tip greater than or equal to 260 m/s and less than or equal to 400 m/s, the pressure ratio and the peripheral speed being measured at cruising speed,
- wherein a thrust density corresponding to each fan rotor blade of the fan section is greater than or equal to 0.5×104 and less than or equal to 3.0×104 N/m2, where the thrust density per blade is defined by the following formula:
- Thrust
-
- density
- =
- F
-
- N
- n
- *
- D
- 2
- *
- 1
-
- 0
-
- 0
- where:
- FN is a thrust generated by the propulsion system and is measured when the propulsion system is stationary at cruising speed in a standard atmosphere and is expressed in Newton;
- n is the number of blades in the fan rotor;
- and
- D is the diameter of the fan rotor, measured in a plane normal to the axis of rotation at an intersection between the top and a leading edge of the fan rotor blades and is expressed in meters, the diameter being greater than or equal to 2.159 m and less than or equal to 3.048 m;
- and
- wherein the thrust, the number of blades, and the diameter are selected such that the thrust generated by the propulsion system is comprised between 18,000 lbf and 51,000 lbf when the propulsion system is stationary, uninstalled, in take-off rating in a standard atmosphere.
A method of operating a fan section of a propulsion system, the fan section comprising a fan rotor comprising at least seventeen blades and at most twenty blades and having a solidity strictly less than 1.0 and optionally strictly greater than 0.6, where the solidity is equal to a ratio between a chord at the blade tip and an inter-blade pitch at the blade tip, the fan section having a hub-tip ratio greater than or equal to 0.22 and less than or equal to 0.32, a pressure ratio greater than or equal to 1.05 and less than or equal to 1.5, and a peripheral speed at the blade tip greater than or equal to 260 m/s and less than or equal to 400 m/s, the pressure ratio and the peripheral speed being measured at cruising speed,
- wherein a thrust density corresponding to each fan rotor blade of the fan section is greater than or equal to 0.5×104 and less than or equal to 3.0×104 N/m2, where the thrust density per blade is defined by the following formula:
- Thrust
-
- density
- =
- F
-
- N
- n
- *
- D
- 2
- *
- 1
-
- 0
-
- 0
- and where:
- FN is a thrust generated by the propulsion system and is measured when the propulsion system is stationary at cruising speed in a standard atmosphere and is expressed in Newton;
- n is the number of blades in the fan rotor;
- and
- D is the diameter of the fan rotor, measured in a plane normal to the axis of rotation at an intersection between the top and a leading edge of the fan rotor blades and is expressed in meters, the diameter being greater than or equal to 2.159 m and less than or equal to 3.048 m;
- and
- wherein the method comprises:
- selecting the thrust, the number of blades, and the diameter such that thrust generated by the propulsion system is comprised between 18,000 lbf and 51,000 lbf when the propulsion system is stationary, uninstalled, in take-off rating in a standard atmosphere, and
- operating the fan section of the propulsion system.
Dependencies are inferred from the claim text.