Augmented cooling for tip clearance optimization

A turbine assembly in a turbine section of an aircraft engine, comprising:

• a turbine rotor including a hub and turbine blades extending outward from the hub to blade tips;
• a turbine housing circumferentially extending and radially surrounding the turbine rotor, the turbine housing having an inner surface facing the blade tips of the turbine blades and an outer surface facing radially outward, the outer surface and the inner surface of the turbine housing spaced apart by an uninterrupted solid thickness of the turbine housing defining a conductive heat transfer path between the outer surface and the inner surface throughout a region of the turbine housing surrounding the turbine blades, a distance between the inner surface of the turbine housing and the blade tips of the turbine blades defining a tip clearance gap;
• and
• a cooling system for optimizing the tip clearance gap, the cooling system including:
• a cooling airflow passage located radially outward from the turbine housing, the cooling airflow passage defined radially between an—the outer surface of the turbine housing and an inner surface of a casing, the casing surrounding the turbine housing within the aircraft engine and being radially spaced apart therefrom, the cooling airflow passage being in heat-transfer communication with the turbine housing and receiving a flow of cooling air therethrough for cooling the turbine housing;
• and
• a heat sink disposed on the outer surface of the turbine housing within the cooling airflow passage, the heat sink including heat transfer elements projecting into the cooling airflow passage away from the outer surface of the turbine housing, the heat transfer elements being in convective heat transfer relationship with the flow of cooling air in the cooling airflow passage.