Fan with variable depth groove casing treatment

A fan case assembly adapted for use with a gas turbine engine, the fan case assembly comprising

• an annular case that extends circumferentially around an axis of the gas turbine engine, and
• a fan track liner coupled to the annular case and including a variable wall assembly having a stationary portion defining at least one groove therein and at least one movable segment arranged in the at least one groove,
• wherein the at least one movable segment is selectively radially translatable within the at least one groove, and wherein radial translation of the at least one movable segment within the at least one groove is configured to alter a flow path across the fan track liner in order to control stall margin of the gas turbine engine and optimize performance of the gas turbine engine, and
• wherein the at least one groove includes a first groove and a second groove defined by the stationary portion, wherein the first groove is axially spaced apart from the second groove, wherein the at least one movable segment includes a first movable segment arranged in the first groove and a second movable segment arranged in the second groove, and wherein the first movable segment and the second movable segment are each independently translatable such that the first and second movable segments are configured to be arranged at the same or different radially positions within the first and second grooves, respectively.

A method comprising

• providing an annular case that extends circumferentially around an axis of a gas turbine engine,
• arranging a fan track liner radially inwardly of the annular case and extending circumferentially at least partway about the axis and coupling the fan track liner to the annular case, the fan track liner including a variable wall assembly having a stationary portion defining a first groove and a second groove therein that each extend circumferentially at least partway about the axis, the first and second grooves being axially spaced apart from each other, the variable wall assembly further having a first movable segment arranged in the first groove and a second movable segment arranged in the second groove, wherein the first and second movable segments each have a first radial extent that is less than a second radial extent of the first and second grooves so as to allow the first and second movable segments to be selectively radially translatable within the first and second grooves, wherein radially inwardly facing surfaces of the first and second movable segments and a radially inwardly facing surface of the stationary portion define a portion of a flow path across the fan track liner, and
• radially translating at least one of the first and second movable segments within the respective first and second grooves so as to alter the portion of the flow path across the fan track liner in order to control stall margin of the gas turbine engine and optimize performance of the gas turbine engine.