Patent ID: 8935913
Filing Date: 2015-01-20
Classification: F01D,F02C,F02K,F04D,F05D,Y02T

Abstract:
1. A gas turbine engine comprising: a fan including a plurality of fan blades rotatable about an axis; a compressor section; a combustor in fluid communication with the compressor section; a turbine section in fluid communication with the combustor, the turbine section including a fan drive turbine and a second turbine, wherein the second turbine is disposed forward of the fan drive turbine and the fan drive turbine includes a plurality of fan drive turbine stages with a ratio between the number of fan blades and the number of fan drive turbine stages is greater than about 2.5; 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 and is configured to rotate at a first speed, the second turbine section has a second exit area and is configured to rotate at a second speed, which is faster than the first speed, wherein the turbine section includes a volume defined within an inner periphery and an outer periphery between a leading edge of a most upstream vane to a trailing edge of a most downstream rotating airfoil and is configured to provide a thrust density greater than 1.5 lbf/in