CN-122014355-A - Power turbine rotor and design method for actively falling off blades of power turbine rotor

Abstract

The invention discloses a power turbine rotor and a design method for actively falling off blades of the power turbine rotor, and relates to the technical field of aeroengines, wherein the power turbine rotor comprises a turbine disk, a flange cavity and a rotor blade, wherein the flange cavity is formed in the circumferential direction of the turbine disk; the blade is provided with a flange plate and a stretching root, the stretching root is positioned below the flange plate, the stretching root is provided with a weak section, the blade is connected onto a rim cavity of the turbine disc through the stretching root, the air baffle is connected below the flange plate of the blade and positioned on the air inlet side of the rim cavity of the turbine disc, the turbine disc is provided with a first mounting part, the flange plate of the blade is provided with a second mounting part, and the air baffle is clamped between the first mounting part and the second mounting part. According to the power turbine rotor provided by the invention, the air baffle is added on the air inlet side of the turbine rotor, the condition that fuel gas flows out of the rim cavity is relieved through the air baffle, and the stability of the aerodynamic performance of the engine is ensured by preventing the fuel gas from overflowing, so that the power turbine rotor is quite beneficial to improving the aerodynamic performance of the engine.

Inventors

• YANG SIYUAN
• AI XING
• YU MING
• LI TIANXIONG
• LI JINGJING
• CHENG HAO
• ZENG JIAXUN
• WU YANGYANG
• WANG TAO
• XU LUBING

Assignees

• 中国航发湖南动力机械研究所

Dates

Publication Date

20260512

Application Date

20260304

Claims (10)

1. 1. A power turbine rotor, comprising: a turbine disc (1) having a rim cavity formed circumferentially thereof; The blade (2) is provided with a flange plate (203) and a root extending part (201), the root extending part (201) is positioned below the flange plate (203), the root extending part (201) is provided with a weak section, and the blade (2) is connected to a rim cavity of the turbine disc (1) through the root extending part (201); The air baffle (3) is connected below the flange plate (203) of the blade (2) and is positioned on the air inlet side of the flange cavity of the turbine disc (1), the turbine disc (1) is provided with a first installation part, the flange plate (203) of the blade (2) is provided with a second installation part, and the air baffle (3) is clamped between the first installation part and the second installation part.
2. 2. The power turbine rotor as claimed in claim 1, characterized in that the turbine disk (1) has a mounting groove (102) in the circumferential direction, the mounting groove (102) having mounting notches (1021) thereon.
3. 3. The power turbine rotor as claimed in claim 2, characterized in that the mounting gap (1021) is provided with a locking groove (1022).
4. 4. The power turbine rotor as claimed in claim 1, wherein the first mounting portion is a first hook (101), an opening of the first hook (101) faces the blade (2), the second mounting portion is a second hook (202), an opening of the second hook (202) faces the turbine disc (1), and the air blocking piece (3) is clamped between the first hook (101) and the second hook (202).
5. 5. The power turbine rotor of claim 4, wherein the groove section of the second hook (202) has a flange straight line segment (2021), a first transition arc segment (2022), a connecting straight line segment (2023) and a second transition arc segment (2024) connected in sequence, and the second transition arc segment (2024) is connected with the root extension (201) of the blade (2).
6. 6. The power turbine rotor as claimed in claim 5, characterized in that the second hooks (202) are formed under the rim plate (203) of the blade (2).
7. 7. The power turbine rotor as claimed in any one of claims 1-6, characterized in that the air baffle (3) has a plurality of pieces.
8. 8. The power turbine rotor as claimed in claim 7, characterized in that a plurality of said air baffles (3) have a plurality of small air baffles (302) and at least one large air baffle (301), the arc length of said large air baffle (301) being greater than the arc length of said small air baffles (302), said large air baffle (301) having radially extending locking strips (3011) thereon.
9. 9. A power turbine rotor according to any one of claims 1-6, characterized in that a damping member (4) is connected between the root portions of two adjacent blades (2), said damping member (4) being hidden under the rim plates (203) of two adjacent blades (2).
10. 10. A method of active blade shedding design for a power turbine rotor according to any one of claims 1 to 9, comprising the steps of: Calculating the breaking rotational speed of the blade (2) by using simulation software, and applying the air baffle (3) to the hook position of the blade (2) in a mass point mode; By the formula Judging whether the blade (2) is broken or not; In the above-mentioned formula(s), The rotation speed is indicated by the number of revolutions, Expressed in rotational speed The maximum strain of the lower blade (2), Representing the maximum strain at any infinitely small increment of rotational speed; when the formula is not satisfied, the blade (2) is not broken, the calculated rotating speed is required to be increased, and continuous attempts are carried out until the formula is satisfied; when the above formula is satisfied, that is, the strain increase rate of the blade (2) is larger than 15% in any small rotation speed increment, the failure of the blade (2) is judged at this time, and the rotation speed at this time is the fracture rotation speed of the blade (2).

Description

Power turbine rotor and design method for actively falling off blades of power turbine rotor Technical Field The invention relates to the technical field of aeroengines, in particular to a power turbine rotor and a design method for actively falling off blades of the power turbine rotor. Background During operation of an aircraft engine, if the power shaft is unfortunately broken, the power turbine rotor continues to idle because of no load, and its rotational speed continues to climb. Once the rotational speed exceeds the burst rotational speed that the disc can withstand, the turbine disc bursts. Fragments generated by bursting have great kinetic energy and are likely to penetrate the engine casing, thus posing a serious threat to the life safety of the crew. Moreover, the burst moment of the wheel disc can cause extremely serious damage to various parts of the engine, and in extreme cases, tragedy of the damaged people can even happen. In view of this severity, turbine rotor blades must be over-rotated for protection. When the turbine rotor blade reaches a certain rotating speed, the turbine rotor blade actively drops off through a specific design. Therefore, the turbine disk loses power for continuously rising the rotating speed, so that the accident that the turbine disk bursts and is more serious is effectively avoided, and the aviation flight safety is guaranteed to the greatest extent. For example, chinese patent document CN103790640B discloses an anti-burst blade of a wheel disc, which is provided with a weak section at a position of the blade near an outer rim of the wheel disc, when the wheel disc approaches to burst rotation speed, the blade is broken preferentially at the weak section, after a single blade is broken, other connected blades are broken successively, after the blade is broken, the wheel disc loses part of power, the broken blade can prevent the wheel disc from rotating, and meanwhile, the wheel disc is severely rocked due to the breaking of the blade to collide with a stationary part of an engine. In the prior art, turbine rotors are typically assembled and secured by a locking tab construction. However, due to the presence of the assembly gap, the aerodynamic performance of the turbine may be reduced, which may adversely affect the thrust (work) weight ratio of the engine. Disclosure of Invention In view of the above, the present invention provides a design method for actively shedding a power turbine rotor and its blades to solve the problem of reduced aerodynamic performance of the turbine due to assembly clearances. The present invention provides a power turbine rotor comprising: a turbine disc having a rim cavity formed circumferentially thereof; The blade, the rim plate and stretch the root, stretch the root to be located the below of rim plate, stretch to have weak section on the root, the blade passes through stretch the root to connect in the circumference of turbine disc; the air baffle is connected below the flange plate of the blade and is positioned on the air inlet side of the flange cavity of the turbine disc, the turbine disc is provided with a first installation part, the flange plate of the blade is provided with a second installation part, and the air baffle is clamped between the first installation part and the second installation part. According to the power turbine rotor provided by the invention, the air baffle is added on the air inlet side of the turbine rotor, the condition that fuel gas flows out from the gap between the lower part of the edge plate of the blade and the turbine disc is relieved through the air baffle, and the stability of the aerodynamic performance of the engine is ensured by preventing the fuel gas from overflowing, so that the power turbine rotor is quite beneficial to improving the aerodynamic performance of the engine. After the power turbine rotor reaches a certain rotating speed, the blades can be actively broken, so that the destructive disaster of bursting of a turbine disk caused by the continuous increase of the rotating speed of the turbine rotor after the breaking of a load shaft of an engine is avoided, the safety of the engine and aircraft personnel is ensured, the impact design difficulty and the weight of a casing are reduced, and the improvement of the thrust (work) weight ratio of the engine and the reduction of the oil consumption rate are facilitated. Optionally, a mounting groove is formed in the circumferential direction of the turbine disk, and a mounting notch is formed in the mounting groove. Optionally, a locking groove is arranged at the mounting notch. Optionally, the first installation department is first couple, the opening of first couple is towards the blade, the second installation department is the second couple, the opening of second couple is towards the turbine dish, the gas barrier joint is in between first couple and the second couple. Optionally, the groove section of the second hook is provided w