A particle separator for use with a gas turbine engine, the particle separator comprising: an adaptive-curvature inner wall arranged circumferentially about an axis, an outer wall arranged circumferentially about the adaptive-curvature inner wall to define an inlet passage of the particle separator, the inlet passage adapted to receive a mixture of air and particles suspended in the air; a splitter located radially between the outer wall and the adaptive-curvature inner wall to separate the mixture of air and particles into a clean flow substantially free of particles and a dirty flow containing the particles during operation of the particle separator, the splitter and the adaptive-curvature inner wall defining an engine channel arranged to receive the clean flow, and the splitter and the outer wall defining a scavenge channel arranged to receive the dirty flow; a control system configured to detect a presence of the particles suspended in the air and to move selectively the adaptive-curvature inner wall between a non-austere arrangement in which the adaptive-curvature inner wall has a first maximum radius and an austere arrangement in which the adaptive-curvature inner wall has a second maximum radius greater than the first maximum radius in response to the control system detecting the presence of the particles; characterised in that the adaptive-curvature inner wall includes a rotor that extends axially relative to the axis, a plurality of leaves arranged circumferentially about the rotor, and a plurality of support struts pivotably coupled to the rotor and pivotably coupled to the plurality of leaves; and in that the control system is configured to rotate selectively the rotor about the axis to move the plurality of leaves radially inward and outward to cause the adaptive-curvature inner wall to move between the non-austere arrangement and the austere arrangement. an adaptive-curvature inner wall arranged circumferentially about an axis, an outer wall arranged circumferentially about the adaptive-curvature inner wall to define an inlet passage of the particle separator, the inlet passage adapted to receive a mixture of air and particles suspended in the air; a splitter located radially between the outer wall and the adaptive-curvature inner wall to separate the mixture of air and particles into a clean flow substantially free of particles and a dirty flow containing the particles during operation of the particle separator, the splitter and the adaptive-curvature inner wall defining an engine channel arranged to receive the clean flow, and the splitter and the outer wall defining a scavenge channel arranged to receive the dirty flow; a control system configured to detect a presence of the particles suspended in the air and to move selectively the adaptive-curvature inner wall between a non-austere arrangement in which the adaptive-curvature inner wall has a first maximum radius and an austere arrangement in which the adaptive-curvature inner wall has a second maximum radius greater than the first maximum radius in response to the control system detecting the presence of the particles; characterised in that the adaptive-curvature inner wall includes a rotor that extends axially relative to the axis, a plurality of leaves arranged circumferentially about the rotor, and a plurality of support struts pivotably coupled to the rotor and pivotably coupled to the plurality of leaves; and in that the control system is configured to rotate selectively the rotor about the axis to move the plurality of leaves radially inward and outward to cause the adaptive-curvature inner wall to move between the non-austere arrangement and the austere arrangement.