Patent ID: 9222417
Filing Date: 2015-12-29
Classification: F02C,F02K,Y02T

Abstract:
1. A gas turbine engine comprising: a combustor; a turbine section in fluid communication with the combustor, the turbine section including a fan drive turbine and a second turbine section, the fan drive turbine including a plurality of turbine rotors; a fan including a plurality of blades rotatable about an axis and a ratio between a number of fan blades and a number of fan drive turbine rotors is between about 2.5 and about 8.5; and a speed change system driven by the fan drive turbine for rotating the fan about the axis; wherein the fan drive turbine has a first exit area at a first exit point and rotates at a first speed, the second turbine section has a second exit area at a second exit point and rotates at a second speed, which is faster than the first speed, wherein a first performance quantity is defined as a product of the first speed squared and the first exit area, a second performance quantity is defined as a product of the second speed squared and the second exit area, and a performance ratio of the first performance quantity to the second performance quantity is between about 0.5 and about 1.5.