US Patent 8109726 Turbine blade with micro channel cooling system

A cooling system for a turbine airfoil of a turbine engine has a multi-pass serpentine flow circuit providing a flow path from a forward cooling flow entry at the root and exhausting towards the trailing edge through a series of chord wise micro channels extending from the rearward pass of the multi-pass serpentine circuit to pressure side bleed slots, each having a forward pressure side lip and opening onto the pressure side adjacent the trailing edge. The micro channels can be formed by a series of spaced fins stacked span wise and extending between the outer wall on the pressure side and the outer wall on the suction side and extending chord wise from the rearward pass to the trailing edge. At least two trip strips can extend from sides of the fins into the micro channels and be staggered relative to trip strips extending into the micro channel from an adjacent fin, whereby turbulent flow levels in the micro channels are increased.