CPC F02C 7/36 (2013.01) [F02K 3/06 (2013.01); F05D 2220/36 (2013.01); F05D 2260/40311 (2013.01); F05D 2260/606 (2013.01)] | 17 Claims |
1. A turbofan engine comprising:
a fan comprising a plurality of rotatable fan blades, each fan blade defining a fan tip speed;
a turbomachine operably coupled to the fan for driving the fan, the turbomachine comprising a compressor section, a combustion section, and a turbine section in serial flow order and together defining a core air flowpath;
a gear box, wherein the turbomachine is operably coupled to the fan through the gear box, wherein a gear ratio of the gear box is greater than or equal to 1.2 and less than or equal to 3.0;
an outer nacelle at least partially surrounding the fan and the turbomachine, the outer nacelle defining a bypass passage with the turbomachine; and
a part span inlet guide vane extending from the outer nacelle at a location forward of the plurality of rotatable fan blades of the fan along an axial direction and aft of an inlet of the outer nacelle,
wherein during operation of the turbofan engine at a rated speed the fan tip speed is greater than or equal to 1000 feet per second, and
wherein the fan defines a fan pressure ratio during operation of the turbofan engine, and wherein during operation of the turbofan engine at the rated speed the fan pressure ratio is less than or equal to about 1.5.
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