Inlet pre-swirl gas turbine engine

A turbofan engine defining an axial direction and a radial direction, the turbofan engine comprising:

• a turbomachine comprising a turbine section with a drive turbine;
• a fan rotatable by the drive turbine of the turbomachine such that the fan is rotatable by the drive turbine at the same rotational speed as the drive turbine, the fan comprising a plurality of fan blades, each of the plurality of fan blades defining a fan blade span along the radial direction;
• an outer nacelle surrounding the plurality of fan blades;
• and
• a plurality of part-span inlet guide vanes cantilevered from the outer nacelle at a location forward of the plurality of fan blades along the axial direction, each of the plurality of inlet guide vanes defining an IGV span along the radial direction, the IGV span being at least about five percent of the fan blade span and up to about fifty-five percent of the fan blade span;
• wherein each part-span inlet guide vane defines a leading edge, a trailing edge, an inner end, and an outer end along the radial direction, wherein each part span inlet guide vane defines a first swirl angle at the trailing edge proximate the inner end and a second swirl angle at the trailing edge proximate the outer end, and wherein the second swirl angle is greater than the first swirl angle.