Fan casing or liner with interchangeable tip treatment segments
View Patent ↗A fan case assembly includes an annular case including a first circumferentially-extending slot formed therein, and a tip treatment segment arranged within the first slot and retained therein. The tip treatment segment includes a radially inwardly-facing segment surface having a tip treatment groove formed therein. The tip treatment segment is selectively removable from and insertable into the first slot and is slidable within and along the first slot such that the tip treatment segment is configured to be selectively positioned within the first slot so as to alter the portion of a flow path across the annular case in order to control stall margin of the gas turbine engine and optimize performance of the gas turbine engine.
1 . A fan case assembly adapted for use with a gas turbine engine, the fan case assembly comprising
an annular case that extends at least partway circumferentially around an axis of a gas turbine engine, the annular case including a radially outwardly-facing surface and a radially inwardly-facing surface opposite the radially outwardly-facing surface, the annular case further including a first slot formed in the radially inwardly-facing surface and extending circumferentially at least partway around the axis,
at least one tip treatment segment arranged within the first slot and retained therein, the at least one tip treatment segment including a radially inwardly-facing segment surface having at least one tip treatment groove formed therein, the radially inwardly-facing segment surface defining a portion of a flow path across the annular case, and
at least one blank wall segment arranged within the first slot,
wherein the at least one tip treatment segment is selectively removable from and insertable into the first slot and is slidable within and along the first slot such that the at least one tip treatment segment is configured to be selectively positioned within the first slot so as to alter the portion of the flow path across the annular case in order to control stall margin of the gas turbine engine and optimize performance of the gas turbine engine,
wherein the first slot is defined by a forward surface and an aft surface spaced apart from the forward surface, and wherein the forward surface faces the aft surface so as to define at least a portion of the first slot therebetween, and
wherein the at least one blank wall segment and the at least one tip treatment segment have an axial extent that spans an axial extent of the first slot, wherein the at least one blank wall segment and the at least one tip treatment segment are formed as single, monolithic components that are separate from each other such that each can be selectively inserted and removed from the first slot without the insertion or removal of the other, wherein the at least one blank wall segment includes no tip treatment groove, wherein the at least one tip treatment segment includes a plurality of tip treatment segments arranged within the first slot at different circumferential positions, wherein at least one of (i) the at least one blank wall segment is arranged circumferentially between and contacting two tip treatment segments of the at plurality of tip treatment segments so as to circumferentially space apart the two tip treatment segments, or (ii) the plurality of tip treatment segments includes a first group of two or more tip treatment segments and a second group of two or more tip treatment segments circumferentially spaced apart from the first group of two or more tip treatment segments, and the at least one blank wall segment is arranged circumferentially between and contacting the first and second groups of two or more tip treatment segments so as to circumferentially space apart the first and second groups of two or more tip treatment segments.
2 . The fan case assembly of claim 1 , wherein the at least one tip treatment segment includes a first tip treatment segment and a second tip treatment segment, and wherein the first and second tip treatment segments are arranged within the first slot at different circumferential positions.
3 . The fan case assembly of claim 2 , wherein a circumferentially-facing surface of the first tip treatment segment contacts a circumferentially-facing surface of the second tip treatment segment such that the first and second tip treatment segments are arranged circumferentially adjacent to each other.
4 . The fan case assembly of claim 3 , wherein the at least one tip treatment groove of the first tip treatment segment is identical to the at least one tip treatment groove of the second tip treatment segment.
5 . The fan case assembly of claim 2 , wherein the first tip treatment segment is circumferentially spaced apart from the second tip treatment segment.
6 . The fan case assembly of claim 1 , wherein the at least one blank wall segment includes a radially inwardly-facing blank wall surface that includes a constant, uninterrupted curvature in the circumferential direction.
7 . The fan case assembly of claim 6 , wherein the radially inwardly-facing blank wall surface, the radially inwardly-facing segment surfaces of the first and second tip treatment segments, and the radially inwardly-facing surface of the annular case are flush with each other so as to define a blank surface across which the flow path extends but for the at least one grooves formed in the first and second tip treatment segments.
8 . The fan case assembly of claim 1 , wherein the annular case further includes a second slot formed in the radially inwardly-facing surface and extending circumferentially at least partway around the axis, the second slot being axially spaced apart from the first slot, and wherein the second slot includes one or more tip treatment segments of the at least one tip treatment segment arranged therein.
9 . The fan case assembly of claim 1 , wherein the at least one tip treatment segment includes a protrusion and the first slot includes a recess formed in an inner surface of the first slot, and wherein the protrusion includes a portion arranged radially outwardly of and that overhangs and rests on a corresponding radially outwardly-facing portion of the recess such that the recess retains the at least one tip treatment segment within the first slot.
10 . The fan case assembly of claim 9 , wherein the recess of the first slot extends circumferentially along a circumferential extent of the first slot and is formed to have a dovetail shape, and wherein the protrusion of the at least one tip treatment segment extends circumferentially along a circumferential extent of the at least one tip treatment segment and includes a dovetail shape that corresponds with the dovetail shape of the recess of the first slot.
11 . The fan case assembly of claim 1 , wherein the annular case is segmented to define an annular case segment, wherein a plurality of annular case segments including the annular case segment are arranged circumferentially adjacent to each other so as to form a full hoop annular ring, and wherein the at least one tip treatment segment is configured to be removed from and inserted into the first slot via a circumferential opening of the first slot located at a circumferential end of the annular case segment.
12 . A fan case assembly adapted for use with a gas turbine engine, the fan case assembly comprising
an annular case or a fan case liner that extends at least partway circumferentially around an axis of a gas turbine engine and including a first slot formed therein and extending circumferentially at least partway around the axis and opening radially inwardly,
a first tip treatment segment arranged within the first slot and retained therein, the first tip treatment segment including a radially inwardly-facing segment surface having a first tip treatment feature formed on the radially inwardly-facing segment surface,
a second tip treatment segment arranged within the first slot, circumferentially spaced apart from the first tip treatment segment, and retained therein, the second tip treatment segment including a radially inwardly-facing segment surface having a second tip treatment feature formed on the radially inwardly-facing segment surface, and
at least one blank wall segment arranged within the first slot circumferentially between the first and second tip treatment segments,
wherein the first and second tip treatment segments are selectively removable from and insertable into the first slot at unique circumferential positions within the first slot such that the first and second tip treatment segments are configured to be selectively positioned within the first slot, wherein the at least one blank wall segment and the at least one tip treatment segment have an axial extent that spans an axial extent of the first slot, wherein the at least one blank wall segment includes no tip treatment groove, and wherein the at least one blank wall segment and the at least one tip treatment segment are formed as single, monolithic components that are separate from each other such that each can be selectively inserted and removed from the first slot without the insertion or removal of the other.
13 . The fan case assembly of claim 12 , wherein the first tip treatment feature formed on the radially inwardly-facing segment surface is a groove formed in the radially inwardly-facing segment surface and opening radially inwardly.
14 . The fan case assembly of claim 13 , wherein the second tip treatment feature formed on the radially inwardly-facing segment surface of the second tip treatment is a groove formed in the radially inwardly-facing segment surface and opening radially inwardly.
15 . The fan case assembly of claim 14 , wherein the annular case or fan track liner further includes a second slot formed therein and extending circumferentially at least partway around the axis and opening radially inwardly, and wherein the second slot includes a third tip treatment segment arranged therein.
16 . The fan case assembly of claim 15 , wherein the groove of the first tip treatment feature of the third tip treatment segment includes a different shape than the grooves of the first and second tip treatment features of the first and second tip treatment segments.
17 . A method comprising
providing an annular case that extends at least partway circumferentially around an axis of a gas turbine engine, the annular case including a radially outwardly-facing surface and a radially inwardly-facing surface opposite the radially outwardly-facing surface,
forming a first slot in the radially inwardly-facing surface of the annular case, the first slot extending circumferentially at least partway around the axis,
forming at least one tip treatment groove in a radially inwardly-facing segment surface of a first tip treatment segment, the radially inwardly-facing segment surface defining a portion of a flow path across the annular case, the first tip treatment segment being selectively removable from and insertable into the first slot and is slidable within and along the first slot,
forming at least one tip treatment groove in a radially inwardly-facing segment surface of a second tip treatment segment, the radially inwardly-facing segment surface defining a portion of a flow path across the annular case, the second tip treatment segment being selectively removable from and insertable into the first slot and is slidable within and along the first slot,
arranging the first tip treatment segment within the first slot and retaining the first tip treatment segment therein,
arranging the second tip treatment segment within the first slot and retaining the second tip treatment segment therein,
arranging at least one blank wall segment within the first slot circumferentially between the first and second tip treatment segments and retaining the at least one blank wall segment therein,
selectively positioning the first and second tip treatment segments and the at least one blank wall segment within the first slot so as to alter the portion of the flow path across the annular case in order to control stall margin of the gas turbine engine and optimize performance of the gas turbine engine,
wherein the first slot is defined by a forward surface and an aft surface spaced apart from the forward surface, and wherein the forward surface faces the aft surface so as to define at least a portion of the first slot therebetween, wherein the at least one blank wall segment and the at least one tip treatment segment have an axial extent that spans an axial extent of the first slot, wherein the at least one blank wall segment includes no tip treatment groove, and wherein the at least one blank wall segment and the at least one tip treatment segment are formed as single, monolithic components that are separate from each other such that each can be selectively inserted and removed from the first slot without the insertion or removal of the other.
18 . The fan case assembly of claim 15 , wherein the first slot is formed in a first portion of the annular case and the second is formed in a second portion of the annular case aft of the first portion, wherein a radially inwardly-facing surface of the first portion is parallel with the axis in an axial direction, and wherein a radially inwardly-facing surface of the second portion is angled relative to the axis in the axial direction.