Fan inlet case strut
A fan inlet case strut including a strut structural section; a strut cover disposed over a portion of the strut structural section; a strut airfoil section formed with a high pressure surface and a low pressure surface connected at a leading edge and a trailing edge and extending from a first end to a second end, a camber line that extends between the leading edge and the trailing edge and a flow feature formed at a strut cover termination.
1 . A fan inlet case strut comprising:
a strut structural section;
a strut cover disposed over a portion of the strut structural section;
a strut airfoil section formed with a high pressure surface and a low pressure surface connected at a leading edge and a trailing edge and extending from a first end to a second end;
a camber line that extends between the leading edge and the trailing edge;
a flow feature formed at a strut cover termination; and
wherein the strut airfoil section comprises a surface that is within a distance aft of the flow feature that extends to the trailing edge; the surface also extends spanwise between the first end and the second end, wherein a thickness of the airfoil along the distance tapers to a minimum thickness such that the surface is flat up to a minimum radius of the trailing edge.
2 . The fan inlet case strut according to claim 1 , wherein the flow feature is formed at the strut cover termination at a predetermined cut back length.
3 . The fan inlet case strut according to claim 1 , wherein the strut airfoil section comprises a profile defined by a camber-angle distribution designed in conjunction with a thickness distribution configured to induce a localized forced non-equilibrium boundary-layer static pressure-rise process.
4 . The fan inlet case strut according to claim 1 , wherein the strut structural section comprises a nominal cross sectional thickness and the fan inlet case strut comprises an extended thickness located beyond the strut cover.
5 . The fan inlet case strut according to claim 4 , wherein the extended thickness is larger than the nominal cross sectional thickness.
6 . The fan inlet case strut according to claim 1 , wherein the flow feature is located at greater than 50% of a chord length of the fan inlet case strut.
7 . A gas turbine engine having a fan inlet case comprising:
a fan inlet case strut formed within the fan inlet case, the fan inlet case strut includes a span dimension extending between and connected with an inner surface and an outer surface of a bypass duct of the gas turbine engine; the fan inlet case strut comprising a strut structural section;
a strut cover disposed over a portion of the strut structural section;
a strut airfoil section formed with a high pressure surface and a low pressure surface connected at a leading edge and a trailing edge and extending from a first end to a second end;
a camber line that extends between the leading edge and the trailing edge; and
a flow feature formed at a strut cover termination; wherein flow feature is formed at the strut cover termination at a predetermined cut back length; wherein the strut structural section comprises a nominal cross sectional thickness and the fan inlet case strut comprises an extended thickness located beyond and external of the strut cover; wherein the extended thickness is larger than the nominal cross sectional thickness.
8 . The gas turbine engine having a fan inlet case according to claim 7 , wherein the strut airfoil section comprises a profile defined by a camber-angle distribution designed in conjunction with a thickness distribution configured to induce a localized forced non-equilibrium boundary-layer static pressure-rise process; wherein the forced non-equilibrium boundary-layer pressure-rise locally generates turbulence production relative to turbulence dissipation in the boundary-layer, enabling the boundary-layer to tolerate a higher local rate of static pressure-rise without separating.
9 . The gas turbine engine having a fan inlet case according to claim 7 , wherein the flow feature is coextensive with a maximum thickness, the flow feature being located at a location greater than 66% of a chord length of the strut airfoil from the leading edge.
10 . The gas turbine engine having a fan inlet case according to claim 7 , wherein the flow feature is located at a location greater than 75% of a chord length of the strut airfoil from the leading edge.
11 . The gas turbine engine having a fan inlet case according to claim 7 , wherein more than one flow feature is formed along a chord length of the strut airfoil.
12 . A process for forming a fan inlet case strut comprising:
forming a strut structural section;
forming a strut cover disposed over a portion of the strut structural section;
forming a strut airfoil section with a high pressure surface and a low pressure surface connected at a leading edge and a trailing edge and extending from a first end to a second end, a camber line that extends between the leading edge and the trailing edge;
forming a flow feature at a strut cover termination, wherein the flow feature comprises a discontinuous surface between the strut cover and the strut structural section; and
locating the flow feature at greater than 50% of a chord length of the fan inlet case strut.
13 . The process of claim 12 , further comprising:
forming the flow feature at the strut cover termination at a predetermined cut back length.
14 . The process of claim 12 , further comprising:
forming the strut airfoil section comprising a profile defined by a camber-angle distribution designed in conjunction with a thickness distribution configured to induce a localized forced non-equilibrium boundary-layer static pressure-rise process; wherein the forced non-equilibrium boundary-layer pressure-rise locally generates turbulence production relative to turbulence dissipation in the boundary-layer, enabling the boundary-layer to tolerate a higher local rate of static pressure-rise without separating.
15 . The process of claim 12 , further comprising:
forming the strut structural section comprising a nominal cross-sectional thickness; and
forming the fan inlet case strut comprising an extended thickness located beyond the strut cover; wherein the extended thickness is larger than the nominal cross-sectional thickness.
16 . The process of claim 12 , further comprising:
forming the flow feature at a location greater than 75% of a chord length of the strut airfoil from the leading edge.
17 . The process of claim 12 , further comprising:
forming more than one flow feature along a chord length of the strut airfoil.