Turbine blade cooling system with bifurcated mid-chord cooling chamber

A turbine blade, comprising:

• a generally elongated blade having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;
• the cooling system, comprising:
• at least one leading edge cooling channel positioned in close proximity to the leading edge of the generally elongated blade;
• at least one trailing edge cooling channel positioned in close proximity to the trailing edge of the generally elongated blade;
• a bifurcated mid-chord cooling chamber positioned between the at least one leading edge cooling channel and the at least one trailing edge cooling channel, wherein the mid-chord cooling channel includes a pressure side serpentine cooling channel in contact with a pressure sidewall of the generally elongated blade and a suction side serpentine cooling channel in contact with a suction sidewall of the generally elongated blade and separated from the at least one pressure side serpentine cooling channel by a mid-chord rib;
• an aperture in the mid-chord rib positioned proximate to an end of the pressure side serpentine cooling channel and a beginning of the suction side serpentine cooling channel of the turbine blade;
• wherein the aperture provides a cooling fluid passageway between the pressure and suction side serpentine cooling channels to exhaust cooling fluids from the pressure side serpentine cooling channel and to supply cooling fluids to the suction side serpentine cooling channel;
• and
• wherein the suction side serpentine cooling channel is positioned relative to the pressure side serpentine cooling channel such that a cooling fluid flow direction through the suction side serpentine cooling channel is generally opposite to the cooling fluid flow in adjacent portions of the pressure side serpentine cooling channel, thereby forming cooling fluid counterflow between the pressure side and suction side serpentine cooling channels.