| 摘要 |
<p>The blade is designed for all boats or ship propellers. The secondary blade has a slot which is located normal to the blade surface and on the outside edge of the blade. The effect of the slot is to reduce the propeller diameter and to increase its pitch. The slot (12) is covered with an aerofoil section (1) along the leading edge of the propeller blade. The blade extends beyond the ends of the slot, which spans only the central portion of the propeller blade.</p> |
