Abstract:
A turbine section including a high pressure turbine, an intermediate pressure turbine and a fan drive turbine, the fan drive turbine driving a gear reduction to in turn drive a fan, and effecting a reduction in the speed of the fan relative to an input speed from the fan drive turbine and said high pressure turbine driving a high pressure compressor, and the intermediate pressure turbine driving a low pressure compressor, with the intermediate pressure turbine having a number of turbine blades in at least one row, and the turbine blades operating at least some of the time at a rotational speed, and the number of turbine blades in the at least one row, and the rotational speed being such that the following formula holds true for the at least one row of the intermediate pressure turbine: (number of blades×speed)/60?5500 Hz.
Abstract:
A gas turbine engine has a fan and a turbine having a fan drive turbine rotor. The fan drive turbine rotor drives a compressor rotor. A gear reduction effects a reduction in the speed of the fan relative to an input speed from the fan drive turbine rotor that drives the compressor rotor. The compressor rotor has a number of compressor blades in at least one of a plurality of rows of the compressor rotor. The blades operate at least some of the time at a rotational speed. The number of compressor blades in at least one row and the rotational speed are such that the following formula holds true for at least one row of the compressor rotor turbine: (number of blades×rotational speed)/60 s≧5500 Hz, and the rotational speed is in revolutions per minute. A method of designing a gas turbine engine and a compressor module are also disclosed.
Abstract:
A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a turbine section including a fan drive turbine, a compressor section driven by the turbine section, a geared architecture driven by the fan drive turbine, and a fan driven by the fan drive turbine via the geared architecture. At least one stage of the turbine section includes an array of rotatable blades and an array of vanes. A ratio of the number of vanes to the number blades is greater than or equal to about 1.55. A mechanical tip rotational Mach number of the blades is configured to be greater than or equal to about 0.5 at an approach speed.
Abstract:
A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a turbine section including a fan drive turbine, a compressor section driven by the turbine section, a geared architecture driven by the fan drive turbine, and a fan driven by the fan drive turbine via the geared architecture. At least one stage of the turbine section includes an array of rotatable blades and an array of vanes. A ratio of the number of vanes to the number blades is greater than or equal to about 1.55. A mechanical tip rotational Mach number of the blades is configured to be greater than or equal to about 0.5 at an approach speed.
Abstract:
An acoustic liner for a gas turbine engine includes an acoustic panel that is curved about a central axis. The acoustic panel includes a support backing, a face sheet, and a cellular structure disposed between the support backing and the face sheet. The face sheet has elongated slots that extend along respective slot centerlines in the plane of the face sheet. The slot centerlines are sloped at oblique angles to the central axis.
Abstract:
A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a turbine section including a fan drive turbine, a geared architecture driven by the fan drive turbine, and a fan driven by the fan drive turbine via the geared architecture. At least one stage of the turbine section includes an array of rotatable blades and an array of vanes. A ratio of the number of vanes to the number blades is greater than or equal to about 1.55. A mechanical tip rotational Mach number of the blades is configured to be greater than or equal to about 0.5 at an approach speed.
Abstract:
In accordance with one aspect of the disclosure, a gas turbine engine, method of using and designing such is disclosed. The gas turbine engine may comprise a fan including a plurality of blades, and a variable area fan nozzle. The fan may be configured to have a design point fan tip leading edge relative flow angle βADP, and may be further configured to have an off-design point fan tip leading edge relative flow angle β at an off-design fan operating point. The variable area fan nozzle may be configured to manipulate the amount of air flowing through the fan so that the absolute value of a difference between the design point fan tip leading edge relative flow angle βADP and the off-design point fan tip leading edge relative flow angle β is in a specified range.
Abstract:
Disclosed is a flutter damper, including an acoustic liner having a perforated radial inner face sheet and a radial outer back sheet, the acoustic liner being configured for peak acoustical energy absorption at a frequency range that is greater than a frequency range associated with fan flutter, a chamber secured to the radial outer back sheet, the chamber being in fluid communication with the acoustic liner, and the chamber being configured for peak acoustical energy absorption at a frequency range that is associated with one or more fan flutter modes, and at least one stiffening structure connected to a top surface of the chamber that tunes the top surface out of the frequency range associated with one or more fan flutter modes.
Abstract:
A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan, a compressor section having a low pressure compressor and a high pressure compressor, a combustor section, and a turbine section having a low pressure turbine, the low pressure turbine for driving the low pressure compressor and the fan; a gear reduction effecting a reduction in the speed of the fan relative to a speed of the low pressure turbine and the low pressure compressor; and at least one stage of the compressor section having a ratio of vanes to blades that is greater than or equal to 1.8. The corrected tip speed of the blades is greater than or equal to 480 ft/sec at an approach speed.
Abstract:
A gas turbine engine has a fan section including a fan, a compressor section including a low pressure compressor and a high pressure compressor, a turbine section including a low pressure turbine and a high pressure turbine, and a gear reduction. The low pressure compressor and the low pressure turbine have a number of blades in each of at least one of a plurality of blade rows. The blades are rotatable at least some of the time at a rotational speed in operation. The number of blades in at least one row and the rotational speed are such that the following formula holds true for at least one row of the compressor rotor turbine: 5500≤(number of blades×rotational speed)/60≤10000, the rotational speed being in revolutions per minute.