GAS TURBINE ENGINE WITH ADAPTIVE TURBINE CLEARANCE CONTROL SYSTEM AND METHOD

Gas turbine engine (20) including a fan (28), compressor, combustion (32), and turbine sections, a fan bypass air path (38), a lubrication system (70), and a turbine active clearance control system (54). The turbine section has a rotor stage and a turbine case clearance control segment (46A). The turbine ACC system includes first (60) and second (64) valves and a heat exchanger (58). The heat exchanger may receive a first fan bypass air flow and a lubricant flow and permits heat transfer therebetween to produce a flow of conditioned air. The first valve receives conditioned air from the heat exchanger. The second valve may receive conditioned air and a second fan bypass air flow. The turbine ACC system may operate in a heating mode in which conditioned air flow, or a combination of conditioned air flow and the second fan bypass air flow is passed to the clearance control segment.