Patent ID: 7367776

Claim:
A turbine engine stator assembly circumferentially spaced apart about a turbine engine rotary blading assembly across a gap having a first radial gap length prior to turbine engine operation, the stator assembly comprising a circumferential shroud having a shroud inner surface defining a first radial boundary of the gap, and the rotary blading assembly comprising blading members having a blading member outer surface defining a second radial boundary of the gap, wherein: the circumferential shroud is movable radially; the stator assembly includes at least one gap control member having a plurality of discrete shape memory ally (SMA) portions comprising at least two different SMA in combination with fluid flow means to deliver fluid at pre-selected temperatures to the SMA portions of the gap control member; the SMA of the gap control member are selected and preconditioned to deform pre-selected amounts during engine operation, responsive to temperature of the fluid, to move the circumferential shroud and the shroud inner surface radially in relation to the blading member outer surface to change the first radial gap length pre-selected amounts during engine operation.