OPEN ROTOR GAS TURBINE ENGINE WITH ADAPTIVE TURBINE CLEARANCE CONTROL SYSTEM AND METHOD

A gas turbine engine (20) disposed within a nacelle (40) includes an open rotor propulsion system (28), compressor (30), combustion (32), and turbine (34) sections, and a turbine active clearance control system (54). The turbine section has a turbine case clearance control segment (46A) disposed radially outside of a rotor stage (44). The turbine active clearance control system includes a bleed air mixing system (60), a nacelle air inlet device (56), and a compressor air bleed structure (58). The turbine active clearance control system is configurable in a turbine case heating mode in which the bleed air mixing system is used to mix an exterior air flow and a compressor bleed air flow to produce a conditioned air flow that is operable to heat the turbine case clearance control segment, and the turbine active clearance control system is configured to direct the conditioned air flow to the turbine case.