Patent ID: 9010085
Filing Date: 2015-04-21
Classification: F01D,F02C,F02K,F05D,Y02T

Abstract:
1. A turbofan engine comprising: an engine case; a gaspath through the engine case; a fan having a circumferential array of fan blades; a compressor in fluid communication with the fan; a combustor in fluid communication with the compressor; a turbine in fluid communication with the combustor, the turbine having a low pressure turbine section having 3 to 6 blade stages; and a speed reduction mechanism coupling the low pressure turbine section to the fan, wherein: a ratio of maximum gaspath radius along the low pressure turbine section to maximum radius of the fan is less than about 0.55; a bypass area ratio is greater than about 6.0; and a ratio of a low pressure turbine section airfoil count to the bypass area ratio is less than about 170.