Heat transfer measurements on a rotating disk with discrete receiver holes

Modern gas turbines are cooled using air diverted from the compressor. In a rotor stator system, the cooling air enters at the center of stator and flows radially outward, then leaves through the discrete receiver holes in the rotor and clearance between rotor and shroud. The rotor with 440 mm diameter has 60 blade-cooling holes with 6 mm diameter at a radius of 195 mm. The temperatures on rotor surface at a number of radial locations were measured by thermocouples. The average Nusselt numbers on the rotating disc Nu_{av, d} and on the surface of receiving holes Nu_{av, b} were determined by experiment results. The magnitude of them was governed by two nondimensional fluid-dynamic parameters: rotational Reynolds number, nondimensional mass flow rate. The experiments reveal that Nu_{av, d} and Nu_{av, b} are increasing as either of them increases. The Nusslet number Nu_{av, d} increases strongly with rotational Reynolds number and weekly with nondimensional mass flow rate compared to the rotating disk without receiver holes.