| 摘要 |
An axial fan comprises a hub (4) and a plurality of blades (S) extending from the hub (4); wherein each blade (5) comprises a main blade portion (9) and a secondary blade portion (10) and the secondary blade portion (10) has a leading edge (10c) adjacent to a leading edge (9d) of the main blade portion (9) and forms a flap for the main blade portion (9); wherein a fluid passage (13) is defined between the leading edge (9d) of the main blade portion (9) and the leading edge (10c) of the secondary blade portion (10); wherein the main blade portion (9) has a main chord (CM) and the secondary blade portion (10) has a secondary chord (CS); and wherein the main chord (CM) and the secondary chord (CS) form a relative attack angle (αR) comprised between 5° and 35°. |
