Variable vane for use in turbo machines

Turbo machines, such as gas turbine engines, have one or more turbine modules, each of which includes a plurality of blades and vanes for exchanging energy with the working medium fluid. Some of the vanes may be fixed and others may be variable, that is, rotatable between positions in the gas turbine engine. A typical vane known in the prior art is shown in FIG. and comprises, generally, a trunnion portion (a) and an airfoil portion (b). The airfoil portion comprises a leading edge (d) and a trailing edge (e). The trunnion portion (a) has an enlarged button portion (f) proximate to a transition zone (g) between the trunnion and airfoil. The variable vane in operation is mounted for rotation about axis (c) so as to locate the position of the leading edge of the airfoil as desired. Generally, the variable vane is rotated through an angle of about 40°. With a turbo machine comprises a trunnion portion and an airfoil portion, the airfoil portion is defined by a leading edge, a trailing edge, and a pair of side edges. One or more of the side edges comprises a fin which extends from proximate to the trunnion portion toward the trailing edge of the airfoil portion. The fin tapers in thickness from the trunnion portion to the trailing edge portion. The fin may extend above and/or below the top and bottom surfaces of the airfoil. The fin may be formed on a portion of one or both of the side edges.