	US 12,291,975 B2
	Blade and slotted rotor wheel for a gas turbine engine
Baptiste Dorian Lawniczek, Moissy-Cramayel (FR); Didier René André Escure, Moissy-Cramayel (FR); and Clémentine Charlotte Marie Mouton, Moissy-Cramayel (FR)
Assigned to SAFRAN AIRCRAFT ENGINES, Paris (FR)
Filed by SAFRAN AIRCRAFT ENGINES, Paris (FR)
Filed on Dec. 15, 2023, as Appl. No. 18/541,057.
Claims priority of application No. 2213618 (FR), filed on Dec. 16, 2022; and application No. 2314119 (FR), filed on Dec. 13, 2023.
Prior Publication US 2024/0209744 A1, Jun. 27, 2024
Int. Cl. F01D 5/30 (2006.01)

CPC F01D 5/3007 (2013.01)

22 Claims

1. A blade comprising:

a root configured to be mounted in a slot of a plurality of slots which opens out at an outer periphery of a rotor disk of a movable wheel of a low-pressure turbine of an aeronautical propulsion system, the rotor disk being centered on a longitudinal axis and the plurality of slots being circumferentially distributed about the longitudinal axis, the root comprising a first platform which has a radially outer surface;

a shroud comprising a second platform which has a radially inner surface; and

an airfoil extending from the root to the shroud, the airfoil having a leading edge and a trailing edge;

wherein a parameter N2S is defined as N2S=π(Re²−Ri²)×w², wherein:

Re is an outer flowpath radius defined as an average of a first radial distance and of a second radial distance, the first radial distance being a distance between the longitudinal axis and a first corner point between the radially inner surface of the second platform and the leading edge, and the second radial distance being a distance between the longitudinal axis and a second corner point between the radially inner surface of the second platform and the trailing edge, the outer flowpath radius Re being in meters;

Ri is an inner flowpath radius defined as an average of a third radial distance and of a fourth radial distance, the third radial distance being a distance between the longitudinal axis and a third corner point between the radially outer surface of the first platform and the leading edge, and the fourth radial distance being a distance between the longitudinal axis and a fourth corner point between the radially outer surface of the first platform and the trailing edge, the inner flowpath radius Ri being in meters;

w is a limit rotation speed intended to be reached by a drive shaft of the aeronautical propulsion system when the aeronautical propulsion system operates at maximum constant power, the movable wheel of the low-pressure turbine of the aeronautical propulsion system being configured to drive in rotation the drive shaft about the longitudinal axis, the limit rotation speed w being in revolutions per minute;

wherein the blade is intended to be subjected to a temperature T when the drive shaft rotates at the limit rotation speed w;

wherein the outer flowpath radius Re and the inner flowpath radius Ri are chosen such that:

if the temperature T is lower than or equal to 700° C., then N2S>33.7×10⁶; and

if the temperature T is greater than 700° C., then N2S>a×T+b, wherein:

a=−0.055;

b=72.2;

T is in degrees Celsius; and

N2S is in 10⁶rpm²·m²; and

wherein the outer flowpath radius Re is comprised in a range from 0.15 to 1.0 meters and the inner flowpath radius Ri is comprised in a range from 0.1 to 0.8 meters.