A turbine airfoil comprising: a leading edge; a trailing edge; a cooling channel extending in a radial direction and tapering inwardly as the cooling channel extends toward the trailing edge, the cooling channel at least partially defined by a pressure side face and a suction side face, the suction side face and the pressure side face extending between a leading edge face and a trailing edge face; a first plurality of turbulators protruding from one of the pressure side face and the suction side face to define a first height, the first plurality of turbulators extending from a leading end to a trailing end toward the trailing edge of the turbine airfoil and spaced radially from each other; and a second plurality of turbulators protruding from the same face as the first plurality of turbulators to define a second height that is less than the first height, the second plurality of turbulators extending from a leading end to a trailing end toward the trailing edge of the turbine airfoil and spaced radially from each other; wherein the trailing ends of the first plurality of turbulators an the leading ends of the second plurality of turbulators are arranged distant from the leading edge face and the trailing edge face of the cooling channel; wherein the second height is less than the first height such that the second plurality of turbulators does not protrude as far away from the respective side face (64, 68) as the first plurality of turbulators; characterized in that each of the plurality of first turbulators comprises a first thickness and each of the plurality of second turbulators comprises a second thickness, that is less than the first thickness, wherein the thickness is the dimension transverse to the protrusion direction and the height of the respective turbulator (70, 74); in that each pair of adjacent turbulators of the first plurality of turbulators comprises a first pitch, each pair of adjacent turbulators of the second plurality of turbulators comprises a second pitch, wherein the second pitch is less than the first pitch; and in that one or more turbulators are extensions, on the leading edge face and/or the trailing edge face, of the turbulators from the suction side face and/or the pressure side face. a leading edge; a trailing edge; a cooling channel extending in a radial direction and tapering inwardly as the cooling channel extends toward the trailing edge, the cooling channel at least partially defined by a pressure side face and a suction side face, the suction side face and the pressure side face extending between a leading edge face and a trailing edge face; a first plurality of turbulators protruding from one of the pressure side face and the suction side face to define a first height, the first plurality of turbulators extending from a leading end to a trailing end toward the trailing edge of the turbine airfoil and spaced radially from each other; and a second plurality of turbulators protruding from the same face as the first plurality of turbulators to define a second height that is less than the first height, the second plurality of turbulators extending from a leading end to a trailing end toward the trailing edge of the turbine airfoil and spaced radially from each other; wherein the trailing ends of the first plurality of turbulators an the leading ends of the second plurality of turbulators are arranged distant from the leading edge face and the trailing edge face of the cooling channel; wherein the second height is less than the first height such that the second plurality of turbulators does not protrude as far away from the respective side face (64, 68) as the first plurality of turbulators; characterized in that each of the plurality of first turbulators comprises a first thickness and each of the plurality of second turbulators comprises a second thickness, that is less than the first thickness, wherein the thickness is the dimension transverse to the protrusion direction and the height of the respective turbulator (70, 74); in that each pair of adjacent turbulators of the first plurality of turbulators comprises a first pitch, each pair of adjacent turbulators of the second plurality of turbulators comprises a second pitch, wherein the second pitch is less than the first pitch; and in that one or more turbulators are extensions, on the leading edge face and/or the trailing edge face, of the turbulators from the suction side face and/or the pressure side face.