Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan and a turbine section including a fan drive turbine and a second turbine. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.

Abstract: A nose cone assembly for a gas turbine engine and method of circulating air in a gas turbine engine are disclosed. The nose cone assembly includes a nose cone having an aperture communicating air to an interior space of the nose cone and a discharge member communicating the air out of the nose cone.

Abstract: A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a shaft and first and second bearing structures that support the shaft. Each of the first bearing structure and the second bearing structure includes a bearing compartment that contains a lubricant and a seal that contains the lubricant within the bearing compartments. A buffer system is configured to pressurize the seals to prevent the lubricant from escaping the bearing compartments. The buffer system includes a first circuit configured to supply a first buffer supply air to the first bearing structure, a second circuit configured to supply a second buffer supply air to the second bearing structure, and a controller configured to select between at least two bleed air supplies to communicate the first buffer supply air and the second buffer supply air.

Abstract: A compressor section is in fluid communication with a fan, which includes a first compressor section and a second compressor section. A turbine section includes a first turbine section driving the fan and the first compressor section and a second turbine section driving the second compressor section and the second compressor rotor. A first performance quantity is defined as a product of the first speed squared and the first area. A second performance quantity is defined as a product of the second speed squared and the second exit area. A performance ratio of the first performance quantity to the second performance quantity is between about 0.2 and about 0.8. A gear reduction is included between the first turbine section and the first compressor section.

Abstract: A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan, a compressor section, and a turbine section including a fan drive turbine and a second turbine. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. A mid-turbine frame is positioned intermediate the fan drive turbine and the second turbine, and can include a bearing support. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a shaft, a first bearing structure and a second bearing structure that support the shaft. Each of the first bearing structure and the second bearing structure includes a bearing compartment that contains a lubricant and a seal that contains the lubricant within the bearing compartments. A buffer system is configured to pressurize the seals to prevent the lubricant from escaping the bearing compartments. The buffer system includes a first circuit configured to supply a first buffer supply air to the first bearing structure, a second circuit configured to supply a second buffer supply air to the second bearing structure, and a controller configured to select between at least two bleed air supplies to communicate the first buffer supply air and the second buffer supply air.

Abstract: A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.

Abstract: A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a performance quantity ratio between about 0.8 and about 1.5.

Abstract: A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with some flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is relatively high.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a turbine section including a fan drive turbine and a second turbine. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. A mid-turbine frame is positioned intermediate the fan drive turbine and the second turbine, and can include a bearing support. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft driving a fan having fan blades. A fan shaft support supports the fan shaft and a gear system is connected to the fan shaft. The gear system includes a gear mesh defining a gear mesh lateral stiffness and a gear mesh transverse stiffness and a reduction ratio greater than 2.3. A gear system input to the gear system defines a gear system input lateral stiffness and a gear system input transverse stiffness. At least one of said gear system input lateral stiffness and said gear system input transverse stiffness is less than 5% of a respective one of said gear mesh lateral stiffness and said gear mesh transverse stiffness.

Abstract: An environmental control system for an aircraft includes a higher pressure tap to be associated with a higher compression location in a main compressor section associated with an aircraft engine, and a lower pressure tap to be associated with a lower pressure location in the main compressor section associated with the aircraft engine. The lower pressure location being at a lower pressure than the higher pressure location. The lower pressure tap communicates to a first passage leading to a downstream outlet, and having a second passage leading into a compressor section of a turbocompressor. The higher pressure tap leads into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive the compressor section of the turbocompressor. A turbine outlet receives airflow exhausted from the turbine section. A compressor outlet receives airflow exhausted from the compressor section.

Abstract: An environmental control system for an aircraft includes a higher pressure tap to be associated with a higher compression location in a main compressor section associated with an aircraft engine, and a lower pressure tap to be associated with a lower pressure location in the main compressor section associated with the aircraft engine. The lower pressure location being at a lower pressure than said higher pressure location. The lower pressure tap communicates to a first passage leading to a downstream outlet, and having a second passage leading into a compressor section of a turbocompressor. The higher pressure tap leads into a turbine section of the turbocompressor such that air in the higher pressure tap drives the turbine section to in turn drive the compressor section of the turbocompressor. A turbine outlet receives airflow exhausted from the turbine section. A compressor outlet receives airflow exhausted from the compressor section.

Abstract: A low pressure compressor for a gas turbine engine includes a low pressure compressor case extending circumferentially around a central axis of the gas turbine engine. The low pressure compressor case includes an inner radial wall surrounding a low pressure compressor rotor and an outer radial wall at least partially defining a fan bypass passage of the gas turbine engine. A low pressure compressor compartment is located between the inner radial wall and the outer radial wall and an electrical component is located in the low pressure compressor compartment. An inlet port at the outer radial wall is configured to admit a cooling airflow into the low pressure compressor compartment from the fan bypass passage to cool the electrical component.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft driving a fan having fan blades, a fan shaft support said that supports fan shaft and a gear system connected to the fan shaft. The gear system includes a ring gear defining a ring gear lateral stiffness and a ring gear transverse stiffness, a gear mesh defining a gear mesh lateral stiffness and a gear mesh transverse stiffness, and a reduction ratio greater than 2.3. At least one of the ring gear lateral stiffness and the ring gear transverse stiffness is less than 12% of a respective one of the gear mesh lateral stiffness and the gear mesh transverse stiffness.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft driving a fan having fan blades supported by a fan shaft support defining a fan shaft support lateral and transverse stiffness. A gear system connected to the fan shaft including a ring gear defining a ring gear lateral and transverse stiffness, a gear mesh defining a gear mesh lateral and transverse stiffness, and a reduction ratio greater than 2.3. At least one of the ring gear lateral and transverse stiffness is less than 12% of a respective one of the gear mesh lateral and transverse stiffness. A flexible support supports the gear system and defines a flexible support lateral and transverse stiffness. At least one of the flexible support lateral and transverse stiffness is less than 11% of a respective one of the fan shaft support lateral and transverse stiffness.

Abstract: A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with some flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is relatively high.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan, a compressor section, and a turbine section including a fan drive turbine and a second turbine. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. A mid-turbine frame is positioned intermediate the fan drive turbine and the second turbine, and can include a bearing support. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.