Turbine engine with composite airfoils
A turbine engine with an engine core defining an engine centerline and comprising a rotor and a stator. The turbine engine including a set of composite airfoils circumferentially arranged about the engine centerline and defining at least a portion of the rotor. An airfoil in the set of composite airfoils including a composite portion extending chordwise between a composite leading edge and a trailing edge and a leading edge protector coupled to the composite portion.
1. A turbine engine, comprising:
an engine core defining an engine centerline and comprising a rotor and a stator;
a first stage of composite airfoils circumferentially arranged about the engine centerline and defining at least a portion of the rotor, a first airfoil of the first stage of composite airfoils comprising:
a first composite portion extending chordwise between a first composite leading edge and a first trailing edge;
a first leading edge protector receiving at least a portion of the first composite leading edge of the first composite portion, the first leading edge protector extending chordwise from a first leading edge towards the first composite portion for a first leading length (FLL); and
the first composite portion and the first leading edge protector together defining an exterior surface of the first airfoil and extending chordwise between the first leading edge and the first trailing edge to define a first chord length (FCL);
a second stage of composite airfoils located downstream of the first stage of composite airfoils and circumferentially arranged about the engine centerline, a second airfoil of the second stage of composite airfoils comprising:
a second composite portion extending chordwise between a second composite leading edge and a second trailing edge;
a second leading edge protector receiving at least a portion of the second composite leading edge of the second composite portion, the second leading edge protector extending chordwise from a second leading edge towards the second composite portion for a second leading length (SLL); and
the second composite portion and the second leading edge protector together defining an exterior surface of the second airfoil and extending chordwise between the second leading edge and the second trailing edge to define a second chord length (SCL);
wherein the FLL and the FCL are related to the SLL and the SCL by a stage protection factor (SPF),
wherein the
S
P
F
=
(
F
L
L
/
F
C
L
)
(
S
L
L
/
S
C
L
)
,
and the SPF is greater than or equal to 0.7 and less than or equal to 4 (0.7≤SPF≤4);
wherein at least one of the first stage of composite airfoils or the second stage of composite airfoils includes a row of individual airfoils, airfoils of the row of individual airfoils including a stagger that increases between a root and a tip to position a leading edge of an airfoil circumferentially adjacent to a suction side of an adjacent airfoil, the row of individual airfoils including no more than twenty two and no less than sixteen airfoils having a solidity defined by a ratio of an airfoil chord over a circumferential pitch greater than or equal to 1.0 and less than or equal to 1.2.
2. The turbine engine of claim 1 wherein the turbine engine is an indirect turbine engine comprising a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a speed reduction device driven by the turbine section, wherein the first airfoil extends spanwise between a first root and a first tip to define a first span length and the second airfoil extends spanwise between a second root and a second tip to define a second span length less than the first span length.
3. The turbine engine of claim 1 wherein the stagger positions a trailing edge of one airfoil circumferentially adjacent to a pressure side of another adjacent airfoil to define an outlet for a flow passage therebetween, and airfoil tips vary in width between leading and trailing edges to converge the flow passage from a mouth to a throat and diverge the flow passage from the throat to the outlet.
4. The turbine engine of claim 1 wherein the airfoils of the row of individual airfoils include a forward aerodynamic sweep at tips thereof, and wherein converging-diverging flow passages at the tips are sized and configured for receiving a supersonic flow of air at leading edges, followed by a shock therein, and with a subsonic diffusion aft from a throat.
5. The turbine engine of claim 1 wherein the SPF is greater than or equal to 0.95 and less than or equal to 2.5 (0.95≤SPF≤2.5).
6. The turbine engine of claim 1 wherein the FLL ranges from 6 cm to 19 cm and the SLL ranges from 1.5 cm to 4 cm.
7. The turbine engine of claim 1 wherein the FCL ranges from 24 cm to 77 cm and the SCL ranges from 9.3 cm to 31 cm.
8. A turbine engine, comprising:
an engine core defining an engine centerline and comprising a rotor and a stator;
a first stage of composite airfoils circumferentially arranged about the engine centerline and defining at least a portion of the rotor, a first airfoil of the first stage of composite airfoils comprising:
a first composite portion extending chordwise between a first composite leading edge and a first trailing edge;
a first leading edge protector receiving at least a portion of the first composite leading edge of the first composite portion, the first leading edge protector extending chordwise from a first leading edge towards the first composite portion for a first leading length (FLL); and
the first composite portion and the first leading edge protector together defining an exterior surface of the first airfoil and extending chordwise between the first leading edge and the first trailing edge to define a first chord length (FCL);
a second stage of composite airfoils located downstream of the first stage of composite airfoils and circumferentially arranged about the engine centerline, a second airfoil of the second stage of composite airfoils comprising:
a second composite portion extending chordwise between a second composite leading edge and a second trailing edge;
a second leading edge protector receiving at least a portion of the second composite leading edge of the second composite portion, the second leading edge protector extending chordwise from a second leading edge towards the second composite portion for a second leading length (SLL); and
the second composite portion and the second leading edge protector together defining an exterior surface of the second airfoil and extending chordwise between the second leading edge and the second trailing edge to define a second chord length (SCL);
wherein the FLL and the FCL are related to the SLL and the SCL by a stage protection factor (SPF),
wherein the
SPF
=
(
F
L
L
/
F
C
L
)
(
S
L
L
/
S
C
L
)
,
and the SPF is greater than or equal to 0.7 and less than or equal to 4 (0.7≤SPF≤4);
wherein at least one of the first stage of composite airfoils or the second stage of composite airfoils includes a row of individual airfoils, airfoils with the row of individual airfoils including a stagger that increases between a root and a tip to position a leading edge of an airfoil of the row circumferentially adjacent to a suction side of an adjacent airfoil of the row to define a mouth for a flow passage therebetween, with the flow passage converging to a throat aft from the mouth, the row of individual airfoils including no more than twenty two airfoils having a solidity defined by a ratio of an airfoil chord over a circumferential pitch to position the leading edge of the row circumferentially near an adjacent tip trailing edge of another airfoil of the row and correspondingly increase the width of the throat.
9. The turbine engine of claim 8 wherein the turbine engine is an indirect turbine engine comprising a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a speed reduction device driven by the turbine section, wherein the first airfoil extends spanwise between a first root and a first tip to define a first span length and the second airfoil extends spanwise between a second root and a second tip to define a second span length less than the first span length.
10. The turbine engine of claim 8 wherein tip solidity is low in magnitude to provide a circumferential gap between the leading and trailing edges of adjacent tips.
11. The turbine engine of claim 8 wherein the stagger positions a trailing edge of one airfoil circumferentially adjacent to a pressure side of another adjacent airfoil to define an outlet for the flow passage therebetween, and airfoil tips vary in width between leading and trailing edges to diverge the flow passage therebetween.
12. The turbine engine of claim 8 wherein the SPF is greater than or equal to 0.95 and less than or equal to 2.5 (0.95≤SPF≤2.5).
13. The turbine engine of claim 8 wherein the FLL ranges from 6 cm to 19 cm and the SLL ranges from 1.5 cm to 4 cm.
14. The turbine engine of claim 8 wherein the FCL ranges from 24 cm to 77 cm and the SCL ranges from 9.3 cm to 31 cm.
15. A turbine engine comprising:
an engine core defining an engine centerline and comprising a rotor and a stator;
a set of composite airfoils comprising a set of fan blades and a set of outlet guide vanes downstream from the set of fan blades, the set of composite airfoils circumferentially arranged about the engine centerline and defining at least a portion of the rotor, an airfoil of the set of composite airfoils comprising:
a composite portion extending chordwise between a composite leading edge and a trailing edge;
a leading edge protector coupled to the composite portion at the composite leading edge to define a seam, and extending chordwise between a leading edge and the seam to define a leading length (LL); and
the composite portion and the leading edge protector together defining an exterior surface of the airfoil and extending chordwise between the leading edge and the trailing edge to define a chord length (CL);
wherein the LL is related to the CL by an airfoil protection factor
(
A
P
F
)
=
(
L
L
)
(
C
L
)
,
a first APF (APF1) for the set of fan blades is greater than or equal to 0.2 and less than or equal to 0.30 (0.2≤APF1≤0.3), and a second APF (APF2) for the set of outlet guide vanes is greater than or equal to 0.08 and less than or equal to 0.17 (0.08≤APF2≤0.17);
wherein at least one of the set of fan blades or the set of outlet guide vanes includes a row of individual airfoils, airfoils of the row of individual airfoils including a stagger that increases between a root and a tip to position a leading edge of an airfoil circumferentially adjacent to a suction side of an adjacent airfoil, the row of individual airfoils including no more than twenty two and no less than sixteen airfoils having a solidity defined by a ratio of an airfoil chord over a circumferential pitch greater than or equal to 1.0 and less than or equal to 1.2.
16. The turbine engine of claim 15 wherein the turbine engine is an indirect turbine engine comprising a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a speed reduction device driven by the turbine section, wherein a first airfoil of the set of fan blades extends spanwise between a first root and a first tip to define a first span length and a second airfoil of the set of outlet guide vanes extends spanwise between a second root and a second tip to define a second span length less than the first span length.
17. The turbine engine of claim 15 wherein tip solidity is low in magnitude to provide a circumferential gap between the leading and trailing edges of adjacent tips.
18. The turbine engine of claim 15 wherein the stagger positions a trailing edge of one airfoil circumferentially adjacent to a pressure side of another adjacent airfoil to define an outlet for a flow passage therebetween, and airfoil tips vary in width between leading and trailing edges to converge the flow passage from a mouth to a throat and diverge the flow passage from the throat to the outlet.
19. The turbine engine of claim 15 wherein the first APF (APF1) relates to the second APF (APF2) by an expression:
APF
1
APF
2
to define a stage protection factor (SPF), wherein the SPF is greater than or equal to 0.95 and less than or equal to 2.5 (0.95≤SPF≤2.5).
20. The turbine engine of claim 15 wherein the composite airfoils in the set of composite airfoils extend spanwise between a root and a tip to define a span length and the APF is determined at a location between 20% and 80% of the span length.
21. The turbine engine of claim 15 wherein the LL ranges from 6 cm to 19 cm for the set of fan blades and from 1.5 cm to 4 cm for the set of outlet guide vanes.
22. The turbine engine of claim 15 wherein the CL ranges from 24 cm to 77 cm for the set of fan blades and from 9.3 cm to 31 cm for the set of outlet guide vanes.
23. A turbine engine comprising:
an engine core defining an engine centerline and comprising a rotor and a stator;
a set of composite airfoils comprising a set of fan blades and a set of outlet guide vanes downstream from the set of fan blades, the set of composite airfoils circumferentially arranged about the engine centerline and defining at least a portion of the rotor, an airfoil of the set of composite airfoils comprising:
a composite portion extending chordwise between a composite leading edge and a trailing edge;
a leading edge protector coupled to the composite portion at the composite leading edge to define a seam, and extending chordwise between a leading edge and the seam to define a leading length (LL); and
the composite portion and the leading edge protector together defining an exterior surface of the airfoil and extending chordwise between the leading edge and the trailing edge to define a chord length (CL);
wherein the leading length (LL) is related to the chord length (CL) by an airfoil protection factor
(
A
P
F
)
=
(
L
L
)
(
C
L
)
and a first APF (APF1) for the set of fan blades is greater than or equal to 0.2 and less than or equal to 0.30 (0.2≤APF1≤0.3) and a second APF (APF2) for the set of outlet guide vanes is greater than or equal to 0.08 and less than or equal to 0.17 (0.08≤APF2≤0.17);
wherein at least one of the set of fan blades or the set of outlet guide vanes includes a row of individual airfoils, airfoils of the row of individual airfoils including a stagger that increases between a root and a tip to position a leading edge of an airfoil of the row circumferentially adjacent to a suction side of an adjacent airfoil of the row to define a mouth for a flow passage therebetween, with the flow passage converging to a throat aft from the mouth, the row of individual airfoils including no more than twenty two airfoils having a solidity defined by a ratio of an airfoil chord over a circumferential pitch to position the leading edge of the airfoil of the row circumferentially near an adjacent tip trailing edge of another airfoil of the row and correspondingly increase the width of the throat.
24. The turbine engine of claim 23 wherein the turbine engine is an indirect turbine engine comprising a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a speed reduction device driven by the turbine section, wherein a first airfoil of the set of fan blades extends spanwise between a first root and a first tip to define a first span length and a second airfoil of the set of outlet guide vanes extends spanwise between a second root and a second tip to define a second span length less than the first span length.
25. The turbine engine of claim 23 wherein tip solidity is low in magnitude to provide a circumferential gap between the leading and trailing edges of adjacent tips.
26. The turbine engine of claim 23 wherein the stagger positions a trailing edge of one airfoil circumferentially adjacent to a pressure side of another adjacent airfoil to define an outlet for the flow passage therebetween, and airfoil tips vary in width between leading and trailing edges to diverge the flow passage therebetween.
27. The turbine engine of claim 23 wherein the APF1 relates to the APF2 by an expression:
A
P
F
1
A
P
F
2
to define a stage protection factor (SPF), wherein the SPF is greater than or equal to 0.95 and less than or equal to 2.5 (0.95≤SPF≤2.5).
28. The turbine engine of claim 23 wherein the composite airfoils in the set of composite airfoils extend spanwise between a root and a tip to define a span length and the APF is determined at a location between 20% and 80% of the span length.
29. The turbine engine of claim 23 wherein the LL ranges from 6 cm to 19 cm for the set of fan blades and from 1.5 cm to 4 cm for the set of outlet guide vanes.
30. The turbine engine of claim 23 wherein the CL ranges from 24 cm to 77 cm for the set of fan blades and from 9.3 cm to 31 cm for the set of outlet guide vanes.