| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a pressure loss in a low-Reynolds number region while securing a reduction effect of the pressure loss in a high-Reynolds number region of an airfoil for an axial-flow type compressor. <P>SOLUTION: In a transonic velocity region whose Reynolds number is not larger than a critical Reynolds number, a shape factor at the back face side of an airfoil has the maximum value in a region of 6% to 15 from the front edge on a code, is substantially stable in a region of 30% to 60, and gradually increases up to 2.5 in a region downstream of 60% of the code. Furthermore, a position in which a flow velocity becomes maximum at the back face of the airfoil remarkably approximates the front edge side compared with a conventional airfoil (CDA). Accordingly, a small impact wave or a group of the impact waves accompanied by layer-flow exfoliation bubbles is generated at the immediate rear of the front edge depending on the state of a transonic velocity inlet air flow, however, since initial transition to a disturbance boundary layer from a layer-flow boundary layer is promoted by the generation of the waves, the disturbance boundary layer at the rear of the back face of the airfoil at the downstream of a transition point is retained in an extremely stable state, thus solving the problem. <P>COPYRIGHT: (C)2012,JPO&INPIT |
