Advanced high turning compressor airfoils

Abstract

In a high turning airfoil capable of being suitably applied to each of blades constituting a blade row of an axial flow-type compressor, both of an intrados generating a positive pressure and an extrados generating a negative pressure exist on one side of a chord line, and the curvature of the extrados made non-dimensional by a chord length has a maximum value between a position corresponding to 10% of the chord length and a position corresponding to 35% of the chord length, and a minimum value in the rear of the position of the maximum value and between a position corresponding to 30% of the chord length and a position corresponding to 50% of the chord length. Preferably, a difference between the maximum value and the minimum value of the curvature is equal to or larger than 0.5, and a turning angle is equal to or larger than 40°. With this airfoil, the total pressure loss coefficient is decreased more than that in an airfoil according to a comparative example in the entire Reynolds number region including medium and high Reynolds number regions and particularly, is decreased remarkably more than that in the airfoil according to the comparative example in a region of low Reynolds number equal to or smaller than 130,000. This is considered because a laminar flow separation region on the extrados of the airfoil is small in the low Reynolds number region, and a phenomenon of reverse flow within bubbles in the laminar flow separation region is weakened.