Airfoil for a turbine nozzle of a gas turbine engine and method of making same

The present invention relates generally to a turbine nozzle for a gas turbine engine and, in particular, to an airfoil utilized therein having at least one of an inner cooling slot and an outer cooling slot at the trailing edge thereof configured to have a variable fillet between a recessed wall and a side wall so as to reduce stress on the airfoil. An airfoil for a turbine nozzle assembly of a gas turbine engine includes an outer side wall, an inner side wall, a leading edge extending from the outer side wall to the inner side wall, a trailing edge extending from the outer side wall to the inner side wall, a concave surface extending from the leading edge to the trailing edge on a pressure side of the airfoil, a convex surface extending from the leading edge to the trailing edge on a suction side of the airfoil, an outer cooling slot, an inner cooling slot, and at least one middle cooling slot formed in the concave side of the airfoil adjacent the trailing edge. Each of the cooling slots further includes a recessed wall, an inner slot side wall, an outer slot side wall, an inner corner fillet located between the inner slot side wall and the recessed wall, and an outer corner fillet located between the outer slot side wall and the recessed wall, wherein one of the inner and outer corner fillets for at least one of the inner and outer cooling slots forms a variable contour from an opening in the concave surface to an exit plane of the trailing edge cooling slots.