Gas turbine engine having composite fan blades

A gas turbine engine defining a radial direction, the gas turbine engine comprising:

• a turbomachine comprising a drive turbine and defining a working gas flowpath and an inlet to the working gas flowpath;
• a fan having a plurality of variable pitch fan blades, a first VPF parameter, and a second VPF parameter, the plurality of variable pitch fan blades including a fan blade formed of a composite material, the fan blade defining a leading edge fan radius RFan_LE and a trailing edge fan radius RFan_TE, and the fan defining a leading edge hub radius RHub_LE and a trailing edge hub radius RHub_TE, the gas turbine engine defining a bypass ratio equal to a mass flowrate of an airflow from the fan over the turbomachine to a mass flowrate of an airflow from the fan through the inlet to the working gas flowpath during operation of the gas turbine engine in a cruise operating mode, the bypass ratio being greater than or equal to 10 and less than or equal to 30;
• and
• a reduction gearbox mechanically coupling the drive turbine of the turbomachine to the fan;
• wherein:
• the gas turbine engine defines a Fan Leading Edge to Trailing Edge Opening Ratio (FLTOR) greater than or equal to 1.03 and less than or equal to 1.5, the FLTOR being equal to:
• R
• Fan
• LE
• -
• R
• Hub
• LE
• R
• Fan
• TE
• -
• R
• Hub
• TE
• the first VPF parameter is defined by a fan blade radius ratio (RR) divided by a fan pressure ratio (FPR) at a static sea-level takeoff operating condition;
• the second VPF parameter is defined by a bearing spanwise force (F_Span) at a redline operating condition measured in pounds force divided by a fan area (F_Area) measured in square inches;
• and
• the first VPF parameter is within a range of 0.10 to 0.40 and the second VPF parameter is within a range of 5.25-30.0 lbf/in2.

A gas turbine engine defining a radial direction, the gas turbine engine comprising:

• a turbomachine comprising a drive turbine and defining a working gas flowpath and an inlet to the working gas flowpath;
• a fan having a plurality of variable pitch fan blades formed of a composite material, a first VPF parameter, and a second VPF parameter, each respective fan blade of the plurality of variable pitch fan blades defining a leading edge fan radius RFan_LE and a trailing edge fan radius RFan_TE, and the fan defining a leading edge hub radius RHub_LE and a trailing edge hub radius RHub_TE, the gas turbine engine defining a bypass ratio equal to a mass flowrate of an airflow from the fan over the turbomachine to a mass flowrate of an airflow from the fan through the inlet to the working gas flowpath during operation of the gas turbine engine in a cruise operating mode, the bypass ratio being greater than or equal to 10 and less than or equal to 30;
• and
• a reduction gearbox mechanically coupling the drive turbine of the turbomachine to the fan;
• wherein:
• the gas turbine engine defines a Fan Leading Edge to Trailing Edge Opening Ratio (FLTOR) greater than or equal to 1.03 and less than or equal to 1.5, the FLTOR being equal to:
• R
• Fan
• LE
• -
• R
• Hub
• LE
• R
• Fan
• TE
• -
• R
• Hub
• TE
• the first VPF parameter is defined by a fan blade radius ratio (RR) divided by a fan pressure ratio (FPR) at a static sea-level takeoff operating condition;
• the second VPF parameter is defined by a bearing spanwise force (F_Span) at a redline operating condition measured in pounds force divided by a fan area (F_Area) measured in square inches;
• and
• the first VPF parameter is within a range of 0.10 to 0.25 and the second VPF parameter is within a range of 2-30.0 lbf/in2.