Double wall airfoil cooling configuration for gas turbine engine

A gas turbine engine comprising:

• a combustor section arranged fluidly between compressor and turbine sections;
• and
• an airfoil arranged in the turbine section, the airfoil including pressure and suction side walls extending in a chord-wise direction between leading and trailing edges, the pressure and suction side walls extending in a radial direction to provide an exterior airfoil surface, a core cooling passage is arranged between the pressure and suction walls in a thickness direction and extends radially toward a tip, an outer cooling passage is arranged in one of the pressure and suction side walls to form a hot side wall and a cold side wall, the hot side wall defines a portion of the exterior airfoil surface, and the cold side wall defines a portion of the core cooling passage, the core cooling passage and the outer cooling passage, and a cooling hole fluidly interconnects the core and outer cooling passages, the cold side wall has a first thickness and a protrusion extending from the cold side wall beyond the first thickness to a second thickness, the cooling hole arranged at least partially in the protrusion.

A casting mold for an airfoil comprising:

• a shell and a core assembly together defining pressure and suction side walls extending in a chord-wise direction between leading and trailing edges, the pressure and suction side walls extending in a radial direction to provide an exterior airfoil surface, a core cooling passage is arranged between the pressure and suction walls in a thickness direction and extends radially toward a tip, an outer cooling passage is arranged in one of the pressure and suction side walls to form a hot side wall and a cold side wall, the hot side wall defines a portion of the exterior airfoil surface, and the cold side wall defines a portion of the core cooling passage, the core cooling passage and the outer cooling passage, and a cooling hole fluidly interconnects the core and outer cooling passages, the cold side wall has a first thickness and a protrusion extending from the cold side wall beyond the first thickness to a second thickness, the cooling hole arranged at least partially in the protrusion.