A rotor wheel for a gas turbine rotor has a first side having a plurality of curved paddles separated by a plurality of curved slots and a second side having a plurality of radial paddles separated by a plurality of radial slots. A method of purging a rotor of a gas turbine includes providing a flow of compressed air between adjacent rotor wheels of the rotor in a radially downward direction on a first side of each wheel and in a radially upward direction on a second side of each wheel; passing the flow through a curved slots on the first side of each rotor wheel; and passing the flow through radial slots on the second side of each rotor wheel.