| 摘要 |
<p>A ship's propeller (5) has an impeller wheel (6) mounted behind it. This impeller wheel has a greater number of blades than the propeller but rotates at a lower speed but in the same direction as the propeller. - The pitch of the part of the impeller blade which lies outside the propeller stream in the radial direction is substantially constant. The pitch of that part lying within the propeller stream increases at a constant rate from the hub outwards.</p> |
