Stator blade and stator blade cascade for axial-flow compressor

摘要

It is an object of the present invention to provide a stator blade for an axial-flow compressor, in which the wave drag due to the generation of a shock wave in a transonic speed range can be suppressed to the minimum. For this purpose, the stator blade in the axial-flow compressor has an intrados producing a positive pressure, and an extrados producing a negative pressure. Both of the intrados and the extrados are located on one side of a chord line. A first bulge and a second bulge are formed on the intrados of the stator blade at a location on the side of a leading edge and on the side of a trailing edge, respectively. Thus, the generation of a shock wave on the extrados can be moderated to reduce the wave drag by positively producing the separation of a boundary layer on the intrados by the first bulge. In addition, the boundary layer rendered unstable by the first bulge on the intrados can be stabilized again by the second bulge on the intrados and hence, the increase in frictional drag due to the separation of the boundary layer on the intrados can be suppressed to the minimum.