CPC F02K 3/06 (2013.01) [F02C 7/045 (2013.01); F02C 7/24 (2013.01); F04D 29/666 (2013.01); F05D 2220/36 (2013.01); F05D 2240/12 (2013.01); F05D 2260/96 (2013.01); F05D 2300/603 (2013.01)] | 20 Claims |
1. A gas turbine engine comprising:
a core turbine engine comprising a low pressure turbine;
a gearbox assembly coupled to the low pressure turbine;
a fan coupled to the gearbox assembly and having a fan diameter and a plurality of fan blades with a blade solidity that is greater than or equal to 0.8 and less than or equal to 2.0;
a blade effective acoustic length (BEAL) defined as:
![]() wherein c is a chord length of a fan blade of the plurality of fan blades, S is a span of the fan blade, rr is a radius ratio of the fan, γ is a stagger angle of the fan blade, and Nb is the number of the plurality of fan blades;
a nacelle that includes a fan case that surrounds the fan, the fan case comprising an inlet disposed forward of the fan and an inlet length, wherein the inlet length is an axial distance between a leading edge of one of the plurality of fan blades and the inlet, as measured at a 75% span position of the fan blade;
a plurality of outlet guide vanes disposed aft of the fan and extending radially between the core turbine engine and the fan case;
an acoustic spacing from the fan blade trailing edge to an outlet guide vane leading edge;
an acoustic spacing ratio (ASR) defined as:
![]() wherein As is the acoustic spacing and Nv is the number of the plurality of outlet guide vanes; and
an inlet-to-nacelle (ITN) ratio defined as a ratio of the inlet length to a maximum diameter of the nacelle,
wherein the ASR of the gas turbine engine is 1.5 to 16.0, and the ITN ratio is 0.23 to 0.35.
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