Turbine component with tip rail cooling passage

A turbine rotor blade for a gas turbine engine, the turbine rotor blade comprising:

• an airfoil having:
• a base, a tip disposed opposite the base, and a pressure sidewall and a suction sidewall extending between a leading edge and a trailing edge thereof;
• an airfoil chamber disposed within the airfoil, the airfoil chamber configured to supply a coolant through the airfoil;
• a tip plate at the tip and a rail extending radially from the tip plate, the rail disposed near or at a periphery of the tip plate, the rail including an inner rail surface, an outer rail surface and a radially outward facing rail surface between the inner rail surface and the outer rail surface;
• a tip rail cavity within and partially circumscribing the rail, the tip rail cavity receiving a coolant flow;
• and
• a tip rail cooling passage including an inlet fluidly coupled to the tip rail cavity, a passage length fluidly coupled to the inlet and partially circumscribing the rail, a metering element fluidly coupled to the passage length, and an outlet fluidly coupled to the metering element and extending through the radially outward facing rail surface.