| 摘要 |
The machine e.g. a fan, has a cylindrical housing (2) around a rotor (1), and a guide wheel (3) downstream of the rotor (1). Upstream or downstream of the latter there is a further auxiliary rotor (4), co-axial with rotor (1), and having blades of a smaller radial size. In the part of the hub of rotor (1) where flow separation is likely, for decreasing the deflection of the relative flow and for this reason for decreasing the blade grid loading, the supply of energy is decreased in the profile sections in question by decreasing the change in the circumferential velocity component of the absolute flow between the inlet and outlet of rotor (1). The auxiliary rotor (4) supplies further energy in these profile sections for keeping substantially constant the design- dependent energy amount in all blade sections. In a modification boundary layer aspiration is used in the region of potential flow separation. Rings (5,9) may be provided. <IMAGE> |
