英国埃克斯特大学课程作业资料(University of Exeter)：船舶的辅助推进系统

Supplementary propulsion systems
辅助推进系统

The efficiency of conventional well-designed propulsion arrangements range 50 - 70% as illustrated in Figure 5-8. The theoretical propulsive efficiency for a given propulsor load (thrust/area ratio) is typically in the range 50 - 97%. Thus, the theoretical maximum gain is in most cases limited to less than 20%, sometimes a bit more if it is possible to increase the propulsor working area (“propeller diameter”) significantly. It should be noted that the theoretical maximum assumes no energy loss in the process of transforming the mechanical energy from the engine into momentum increase of the water, something that is not very realistic.
传统精心设计的推进安排范围50 - 70％的效率，如图5-8所示。对于一个给定的推进器的负载（推力/面积比）的理论推进效率一般是在范围为50 - 97％。因此，理论上的最大增益在大多数限于小于20％的情况下，有时会多一点，如果它是可以显着增加推进器的工作区（“螺旋桨直径”）。应该指出的是理论上的最大值假定在从发动机的机械能转化成水的动量增加的过程中，没有能量损失，这是不太现实的。

Figure 5-8 - Propulsive efficiency of different propulsion systems
图5-8 - 不同的推进系统推进效率

It is clear that there is limited room for innovative solutions to revolutionise ship propulsion. There have been some original inventions over the years, like the Whale Tail Propulsion systemand different versions of the paddle wheel. The possible advantage of those systems is that they apply a relatively larger propulsion area. Thus, they have a higher theoretical efficiency.
很清楚，创新的解决方案，彻底改变船舶推进的空间有限。多年来，已经有一些原创性发明，像鲸尾推进系统和不同版本的桨轮。这些系统的可能的优点是，它们适用于一个相对较大的推进区。因此，它们具有更高的理论效率。

However, they are mechanically more complex than the screw propeller, which adds weight and increase mechanical losses. The paddle wheels also have a lower efficiency converting mechanical energy into thrust. It seems unlikely that any of these inventions will have any impact on the energy consumption of the world fleet.
然而，他们是机械复杂得多的螺旋推进器，这增加了重量，并增加机械损失。该叶轮也有一个较低的效率，机械能转化为推力。这似乎不大可能，这些发明将在世界船队中的能量消耗没有任何影响。

In the seventies and eighties there were several attempts to use sails and wind power as supplementary propulsion on fairly large merchant vessels. While upwards of 25 vessels, from
50 to 50,000 tons have either been retrofitted or studied for sail retrofit [Bergeson and Greenwald, 1982   #p#分页标题#e#http://ukthesis.org/ygsslwdx/  ; Priebe, 1986], there is little or no commercial interest in sails as supplementary propulsion today. The reason for this is the same as it was 100 years ago; fuel oil is inexpensive, powered vessels are not labour intensive and powered vessels' performance is both reliable and repeatable. Currently envisioned concepts for sails as supplementary propulsion result in average fuel savings throughout a vessel's voyage on the order of 10-30% [Bergeson and Greenwald, 1982; MacAlister, 1982]. With anything near the current bunker price, this is not enough saving to warrant the investment, additional maintenance and crew requirements, as well as the restrictions the sailing gear will put on the use of deck space.
在七十年代和八十年代，有几个尝试使用帆和风力发电作为补充相当大的商船上推进。虽然只有25艘船舶，从50吨至50,000吨以上被改装或研究帆改造[Bergeson和格林沃尔德，1982年PRIEBE，1986]，很少或没有商业利益帆今天作为补充推进。这样做的原因是一样的，因为在100年前，燃料油价格低廉，马力船只不是劳动密集和动力船只，性能是可靠和可重复的。

Wave propulsion is another supplementary propulsion system, where fixed or movable foils in the bow region provides a thrust produced by the vertical motion of the bow relative to the surrounding waves. This concept works well as long as the relative vertical motions are large, which is the case for relatively small vessels moving in head seas of suitable length and height.
波推进器是另一种辅助推进系统，其中在船头区域，固定的或可移动的金属箔提供了一个推力，所产生的垂直运动相对于周围的波弓。这个概念运作良好，只要相对垂直运动很大，这是合适的长度和高度的头海域移动的情况下，相对较小的船只。

Thus, the number of ships where this concept would be applicable is small, and the gain for those ships is also small, since the period of time when the wave conditions are suitable is small.
因此，这个概念将适用于小的船舶数量，这些船舶的收益也小，因为波条件适合时，时间也是短的。