Abstract: A fan section for a gas turbine engine according to an example of the present disclosure includes, among other things, a fan rotor having fan blades, and a plurality of fan exit guide vanes positioned downstream of the fan rotor. The fan rotor is configured to be driven through a gear reduction. A ratio of a number of fan exit guide vanes to a number of fan blades is defined. The fan exit guide vanes are provided with optimized sweep and optimized lean.

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.

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: (number of blades×rotational speed)/60 s?5500 Hz, and the rotational speed is in revolutions per minute.

Abstract: A gas turbine engine has a propulsor including a fan and a liner positioned upstream of the fan. The liner has a backing plate, a cellular structure with cells extending from the backing plate, and a perforated sheet with a depth defined as a distance between the perforated sheet and the backing sheet. The depth is selected to achieve a desired ratio of the depth relative to a gap?. A depth to gap ratio is substantially in a range of 0.035 to 0.08. A method is also disclosed.

Abstract: Bleed valve assemblies in a gas turbine engine are disclosed herein. A bleed valve assembly in a low pressure compressor may include a bleed valve and a resonator chamber. A manifold may allow passage of air from a bleed duct into the resonator chamber. The resonator chamber may alter resonation properties of the bleed duct in order to prevent damage to components in the low pressure compressor.

Abstract: A gas turbine engine has a fan, a turbine section having a first turbine including a first turbine rotor, a compressor rotor, and a gear reduction that effects a reduction in a speed of the fan relative to an input speed from the first turbine rotor. Each of the compressor rotor and the first turbine rotor includes a number of blades in each of a plurality of blade rows, the number of blades configured to operate at least some of the time at a rotational speed, and the number of blades and the rotational speed being such that the following formula holds true for at least a plurality of the blade rows of the first turbine rotor: (number of blades×rotational speed)/60?5500, and the rotational speed being an approach speed in revolutions per minute, and the following formula holds true for at least a plurality of the blade rows of the compressor rotor: (number of blades×rotational speed)/60?10000, the rotational speed being an approach speed in revolutions per minute.

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, and having a gear reduction ratio of greater than 2.5:1. 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: (number of blades×rotational speed)/60 sec?5500 Hz, and the rotational speed is in revolutions per minute. A method of designing a gas turbine engine also disclosed.

Abstract: A gas turbine engine has a fan, a turbine section having a first turbine including a first turbine rotor, a compressor rotor, and a gear reduction configured to effect a reduction in a speed of the fan relative to an input speed from the first turbine rotor. Each of the compressor rotor and the first turbine rotor includes a number of blades in each of a plurality of blade rows, the number of blades configured to operate at least some of the time at a rotational speed, and the number of blades and the rotational speed being such that the following formula holds true for at least a majority of the blade rows of the first turbine rotor, but does not hold true for any of the blade rows of the compressor rotor: (number of blades×rotational speed)/60?5500, and the rotational speed being an approach speed in revolutions per minute.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan, a turbine section that has a fan drive turbine rotor, and a compressor rotor. A gear reduction effects a reduction in a speed of the fan relative to an input speed from the fan drive turbine rotor. The compressor rotor has a number of compressor blades in at least one of a plurality of blade rows of the compressor rotor, and the blades are configured to operate at least some of the time at a rotational speed. The number of compressor blades in at least one of the blade rows and the rotational speed are such that the following formula holds true for the at least one of the plurality of blade rows of the compressor rotor: (the number of blades×the rotational speed)/60 sec?about 5500 Hz. A method of designing a gas turbine engine is also disclosed.

Abstract: A gas turbine engine has a fan, a turbine section having a first turbine including a first turbine rotor, a compressor rotor, and a gear reduction configured to effect a reduction in a speed of the fan relative to an input speed from the first turbine rotor. Each of the compressor rotor and the first turbine rotor includes a number of blades in each of a plurality of blade rows, the number of blades configured to operate at least some of the time at a rotational speed, and the number of blades and the rotational speed being such that the following formula holds true for at least a majority of the blade rows of the first turbine rotor, but does not hold true for any of the blade rows of the compressor rotor: (number of blades×rotational speed)/60?5500, and the rotational speed being an approach speed in revolutions per minute.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan, a turbine section that has a fan drive turbine rotor, and a compressor rotor. A gear reduction effects a reduction in a speed of the fan relative to an input speed from the fan drive turbine rotor. The compressor rotor has a number of compressor blades in at least one of a plurality of blade rows of the compressor rotor, and the blades are configured to operate at least some of the time at a rotational speed. The number of compressor blades in at least one of the blade rows and the rotational speed are such that the following formula holds true for the at least one of the plurality of blade rows of the compressor rotor: (the number of blades×the rotational speed)/60 sec?about 5500 Hz. A method of designing a gas turbine engine is also disclosed.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan, a turbine section having a fan drive turbine rotor, and a compressor rotor. A gear reduction is configured to effect a reduction in a speed of the fan relative to an input speed from the fan drive turbine rotor. Each of the compressor rotor and the fan drive turbine rotor includes a number of blades in each of a plurality of blade rows. The number of blades are configured to operate at least some of the time at a rotational speed.

Abstract: A gas turbine engine has a fan, a turbine section having a first turbine including a first turbine, a compressor, and a gear reduction positioned between the fan and the first turbine. Each of the compressor and the first turbine includes a number of blades in each of a plurality of blade rows, the number of blades rotatable at least some of the time at a rotational speed in operation, and the number of blades and the rotational speed being such that the following formula holds true for the plurality of the blade rows of the first turbine, but does not hold true for any of the blade rows of the compressor rotor: (number of blades×rotational speed)/60?5500, and the rotational speed being an approach speed in revolutions per minute.

Abstract: A gas turbine engine has a fan including a plurality of fan blades, a turbine section having a first turbine, a compressor, and a gear reduction positioned between the fan and the first turbine. Each of the compressor and the first turbine includes a number of blades in each of a plurality of blade rows, the number of blades rotatable at least some of the time at a rotational speed in operation, and the number of blades and the rotational speed being such that the following formula holds true for at least a majority of the blade rows of the first turbine, but does not hold true for any of the blade rows of the compressor: (number of blades×rotational speed)/60?5500, and the rotational speed being an approach speed in revolutions per minute.

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 disclosed fan section of a gas turbine engine includes a fan rotor having a plurality of fan blades and a duct defining a passageway aft of the fan rotor. A fan exit guide vane is disposed within the duct downstream of the fan blades. The fan exit guide vane includes a plurality of exit guide vanes positioned downstream of the fan rotor with at least two of the plurality of exit guide vanes including different aft geometries for guiding airflow through the passage to reduce pressure distortions at the fan blades.

Abstract: A disclosed fan section of a gas turbine engine includes a fan rotor having a plurality of fan blades and a duct defining a passageway aft of the fan rotor. A fan exit guide vane is disposed within the duct downstream of the fan blades. The fan exit guide vane includes a plurality of exit guide vanes positioned downstream of the fan rotor with at least two of the plurality of exit guide vanes including different aft geometries for guiding airflow through the passage to reduce pressure distortions at the fan blades.

Abstract: An exemplary section of a gas turbine engine according to this disclosure includes, among other things, a first array of airfoils including a first number of airfoils, and a second array of airfoils downstream of the first array of airfoils. The second array includes a second number of airfoils. The second number of airfoils is at least 1.19 times the first number of airfoils thereby providing a predetermined modal.

Abstract: A gas turbine engine impact liner is disclosed. The impact liner may include a base sheet, a plurality of stanchions extending from the base sheet, and a plurality of supports, each being operatively associated with one of the plurality of stanchions.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan, a turbine section having a fan drive turbine rotor, and a compressor rotor. A gear reduction is configured to effect a reduction in a speed of the fan relative to an input speed from the fan drive turbine rotor. Each of the compressor rotor and the fan drive turbine rotor includes a number of blades in each of a plurality of blade rows. The number of blades are configured to operate at least some of the time at a rotational speed.