a gas turbine engine assembly includes a housing including an annular duct wall that at least partially defines a mainstream hot gas flow path ; a stator assembly with a stator vane extending into the mainstream gas flow ; and a turbine rotor assembly upstream of the stator assembly and defining a turbine cavity with the stator assembly . the turbine rotor assembly includes a rotor disk having a forward side and an aft side , a rotor platform positioned on a periphery of the rotor disk , the rotor platform defining an aft flow discourager , a rotor blade mounted on the rotor platform extending into the mainstream gas flow , and an aft seal plate mounted on the aft side of the rotor disk . the aft seal plate has a radius such that the aft seal plate protects the rotor disk from hot gas ingestion .