Variable pitch fans for turbomachinery engines
A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in 2 . In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in 2 . In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.
1. A turbomachinery engine comprising:
a fan assembly including a plurality of fan blades, a first VPF parameter, and a second VPF parameter, wherein:
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 0.1 to 0.25 and the second VPF parameter is within a range of 2-30 lbf/in 2 , or the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in 2 ;
a pitch change mechanism coupled to the plurality of fan blades and configured for adjusting a pitch of the plurality of fan blades;
a vane assembly including a plurality of vanes disposed aft of the fan blades;
a core engine including one or more compressor sections and one or more turbine sections; and
a gearbox including an input and an output, wherein the input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, wherein the output is coupled to the fan assembly and has a second rotational speed which is less than the first rotational speed.
2. The turbomachinery engine of claim 1 , wherein the plurality of fan blades is 8-20 fan blades.
3. The turbomachinery engine of claim 1 , wherein the plurality of fan blades is 12-16 fan blades.
4. The turbomachinery engine of claim 1 , wherein the plurality of fan blades is 12-14 fan blades.
5. The turbomachinery engine of claim 1 , wherein the RR is within a range of 0.125-0.55.
6. The turbomachinery engine of claim 1 , wherein the RR is within a range of 0.2-0.5.
7. The turbomachinery engine of claim 1 , wherein the RR is within a range of 0.25-0.35.
8. A turbomachinery engine comprising:
a fan assembly including a plurality of variable pitch fan blades, a first VPF parameter, and a second VPF parameter, wherein:
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 0.1 to 0.25 and the second VPF parameter is within a range of 2-30 lbf/in 2 ;
a core engine including one or more compressor sections and one or more turbine sections; and
a gearbox including an input and an output, wherein the input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, wherein the output is coupled to the fan assembly and has a second rotational speed which is less than the first rotational speed.
9. The turbomachinery engine of claim 8 , further comprising a pitch change mechanism coupled to the plurality of variable pitch fan blades and configured for adjusting a pitch of the plurality of variable pitch fan blades.
10. The turbomachinery engine of claim 8 , wherein the pitch change mechanism is a linear actuated pitch change mechanism.
11. The turbomachinery engine of claim 8 , wherein the plurality of fan blades is 10-18 fan blades.
12. The turbomachinery engine of claim 8 , wherein the plurality of fan blades is 12-14 fan blades.
13. The turbomachinery engine of claim 8 , wherein the plurality of fan blades is exactly 14 fan blades.
14. The turbomachinery engine of claim 8 , wherein the RR is within a range of 0.125-0.55.
15. A turbomachinery engine comprising:
a fan assembly including a plurality of variable pitch fan blades, a first VPF parameter, and a second VPF parameter, wherein:
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/in 2 ;
a core engine including one or more compressor sections and one or more turbine sections; and
a gearbox including an input and an output, wherein the input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, wherein the output is coupled to the fan assembly and has a second rotational speed which is less than the first rotational speed.
16. The turbomachinery engine of claim 15 , further comprising a linear actuated pitch change mechanism coupled to the fan assembly and configured for adjusting a pitch of the plurality of variable pitch fan blades.
17. The turbomachinery engine of claim 15 , wherein the plurality of fan blades is 12-16 fan blades.
18. The turbomachinery engine of claim 15 , wherein the plurality of fan blades is 12-14 fan blades.
19. The turbomachinery engine of claim 15 , wherein the RR is within a range of 0.125-0.55.
20. The turbomachinery engine of claim 15 , wherein the RR is within a range of 0.2-0.5.