Airfoil shape of stationary blade for axial flow type compressor

摘要

The object of the present invention is to reduce pressure loss in an axial-flow compressor by suppressing secondary flow on the suction surface (SS). To achieve this, a vane for an axial-flow compressor is presented in which a pressure surface (PS) generates positive pressure and a suction surface generates negative pressure, and both are located on one side of the chord line. Furthermore the pressure surface includes a bulging portion (CV) having a maximum curvature of 1.5 or more, between a chordal position of 70% and 95%, in a central section of the vane's span. This configuration increases the flow velocity around the bulging portion (CV) of the pressure surface to locally decrease the static pressure. By flow continuity the flow velocity on the suction surface that faces the pressure surface is decreased, and thus locally the static pressure on the suction surface is increased. As a result, the secondary flow, which would flow from the pressure surface with positive pressure to the suction surface with negative pressure from the hub region, is suppressed as a result of the locally increased static pressure on the suction surface. Therefore the pressure loss, which would be caused by the secondary flow, can be reduced.