Low noise turbine for geared turbofan engine
AssigneesUnited Technologies Corporation, MTU Aero Engines AG
InventorsBruce L. Morin, Detlef Korte
Life of this patent
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Abstract
A gas turbine engine is utilized in combination with a gear reduction to reduce the speed of a fan relative to a low pressure turbine speed. The gas turbine engine is designed such that a blade count in the low pressure turbine multiplied by the speed of the low pressure turbine will result in operational noise that is above a sensitive range for human hearing. A method and turbine module are also disclosed.
Claims20
A gas turbine engine comprising:
- a fan, a compressor section including a compressor having a low pressure portion and a high pressure portion, a combustor section, and a turbine having a low pressure portion;
- a gear reduction effecting a reduction in the speed of said fan relative to an input speed to said fan;
- said low pressure portion of said turbine having a number of turbine blades in each of a plurality of rows of said turbine portion, and said low pressure turbine blades operating at least some of the time at a rotational speed, and said number of blades and said rotational speed being such that the following formula holds true for at least one of the blade rows of the low pressure turbine
- (number of blades×speed)/60≧5500;
- and
- said rotational speed being an approach speed in revolutions per minute.
A method of designing a gas turbine engine comprising the steps of including a gear reduction between a low pressure turbine portion and a fan, and selecting the number of blades in each row of the low pressure turbine portion rotors, in combination with the rotational speed of the low pressure turbine, such that the following formula holds true for at least one of the blade rows of the low pressure turbine:
- (number of blades×speed)/60≧5500;
- and
- said rotational speed being an approach speed in revolutions per minute.
A turbine module comprising:
- a low pressure turbine portion having a number of turbine blades in each of a plurality of rows of said low pressure turbine portion, and said low pressure turbine portion operating at least some of the time at a rotational speed, and said number of blades and said rotational speed being such that the following formula holds true for at least one of the blade rows of the low pressure turbine portion
- (number of blades×speed)/60≧5500;
- and
- said rotational speed being an approach speed in revolutions per minute.
Dependencies are inferred from the claim text.