【转hefengeagle】技术讨论贴--船姿的调整--解决你一直想解...

twototoo

前两天自己很久以前的帖子被挖出来了........  undefined ..........

http://bbs.5imx.com/bbs/forum.php?mod=viewthread&tid=680065
不但引得我等辈纷纷讨论，也引得各路大神分分发话..... 这个紧张阿.......

调船本是高深之事，抛砖引玉，翻译一篇文章，供大家讨论拍砖{:3_61:}{:3_61:}{:3_61:}{:1_61:}{:1_61:}.

原文地址：http://www.modelpowerboat.com/
其他文章大概内容和我早先发出的文章差不多，还有很多油船的资料，谐振管设计，发动机调教之类的...... 油船高人要是有功夫，帮忙翻译下。


RC BOAT HULL ATTITUDE
--船姿的调整

What we call attitude is the way a R/C boat behaves on water. This page explains the theory to help get the best performance out of your R/C Model Boat. Theoretically, when moving a perfect boat should:
o        have a reduced wet area: just a minimum part of the hull touching the water
o        not have prop walk: tendency to turn right even with the rudder on a neutral position
o        have no tendency to chine walk: side to side movements when traveling in a straight line
o        have no tendency to porposing: bow oscillation, up and down when traveling in a straight line
o        have no tendency to torque roll: rolling to the starboard as a reaction to the engine torque
o        be stable: not slip too much and not roll on turns.
我们所说的船姿势是说船体在水面行使的姿态。下面我们从理论方面来探讨如何让模型船获得最好的表现，理论上来说，最好的航姿包括：
        * 最少的浸水面，只有很小的一部分船体触水
        * 没有侧滑，只要舵片安装正确，船体直行
        * 直线行使的时候，没有左右摆动
        * 直线行使的时候，没有上下的跳动
        * 没有因为电机反扭造成的船体不平
        稳定，转弯时没有大幅度的侧滑

This is the theory. In practice, things happen in a slightly different way. There is not such thing as an ideal boat and so, we must adjust it to make it behave as close to this ideal as possible. Let's exam each on of those items and discuss how to correct "bad habits".
这是从理论方面来说的。实际上，往往通过不同的形式表现。没有所谓的完美船，我们要不断调船使其接近完美。下面我们来谈谈如何调整每一个项目

Before any adjustment, it's important to have in mind that a boat on the water is in equilibrium over two lines. One of them cuts it from bow to transom and other transverses from port to starboard, at the boat's Center of Gravity - CG. This understanding is important to make it clear that all adjustments are complexes and seldom produce a single effect. For instance, lifting the transom makes the bow go down into water as a consequence. Lifting starboard makes the port side deep into water. To extend the prop far from the transom to reduce prop walk may result in porpoising. In other words, whatever you do in one side induces a counter-reaction on the opposite side; sometimes correcting a problem causes another.
开始调整之前，有个概念十分重要“船体在水中航行要保持在两条线上的平衡，一条是从船头到船尾的纵向中线，另一条是从左舷到右舷的横向中线，船体的重心在这两条线上。理解了这个，就可以明白任何一个微小的调整都会产生复杂的结果。例如：提升右舷而增加左舷的浸水；增加出轴可以减少向右偏的趋势但却可能导致船体跳动。换句话来说，任何一方面的调整，都会反作用另一方面，一方面纠正问题，一方面产生问题。

Center of Balance - CB: line that cuts the boat in two halves from bow to transom. Movements from starboard to port or v.v. occur alongside this line.
平衡中心：一条从船头到船尾的中线。船体左右晃动是沿着这条中线的。

Center of Gravity - CG: point of equilibrium of the boat, between bow and transom. Bow to transom movements occur over a shaft that runs through this point.
重心：船体的平衡点，在船头和船尾之间。船体的跳动沿着这个重心。

The higher over the CB the Center of Gravity, the higher the tendency for the boat to lean on turns. Higher/heavier engines tends to raise the CG - the farther from the keel the CG, more unstable the boat will be. Compare the race cars with their street cousins: lower=more stable.
重心越高，船体转弯时倾斜度越高，发动机安装较高，会提升船体的重心，船体就越不稳定。可以对比一下跑车，低底盘带来更高的转弯稳定性。

Wet area: the smaller the portion of the boat in contact with the water, the higher the speed. This is pretty obvious because the drag of the hull is proportional to the area in contact with the water. The limit is attained when the wet area is so small that we lost the control of the boat.
浸水面：船体高速行使时和水的接触面，显而易见，浸水面的大小和水对船体的托拽是正比的。但是，如果浸水面过小，我们将失去对船的操控。

How to correct the attitude of the boat

如何调船

Center of Gravity: The chapter How to Assemble a R/C Boat, in the Technical session, shows how to calculate and adjust the CG. It's easy to understand that a CG towards the front tends to maintain the bow down into water, increasing the wet area and hampering the planning of the boat when at speed. On the other side, a CG too close to the transom tends to raise the bow too much, making the boat unstable at speed. As a rule of thumb, CG must be between 27% and 30% of the total length of the boat, measured from transom, for a completely assembled boat - ready to run except for the fuel. As very powerful engines tend to raise the boat's bow, under those circumstances a CG over the upper limit (30%) may be advisable. On the other hand, mild engines will be happy with the 27% rule.

重心：在装船的一章里面我们说明如何计算和调整重心。很容易理解，重心靠前，会压头，增加浸水面，阻碍船体起划。另一方面，重心靠后，会升水，降低船体的稳定性。经验来说，重心一定是在从船尾向船头方面的船体总长的27%-30%处(对于一条装好的船，油船不包括燃料，电船包括电池)。强有力的发动机会抬起船头，这种情况下重心超过30%处也是可以的。反之亦然。

Strut angle: A strut has a positive angle when the prop shaft points upwards, far from the water surface. In this situation, the transom is pressed down. A negative angle occurs when the prop shaft points down, towards the water surface, raising the transom. If you imagine the boat supported on a transverse shaft that goes exactly through the CG, it's easy understand that, when the transom is lowered the bow goes up, reducing the wet area. The contrary occurs with a negative angle for the strut. Although apparently we could use the strut angle to correct any incorrect attitude, the truth is that the neutral angle is the ideal, just a few degrees off are allowed to adjust the wet area. If more than 2 degrees are necessary, something else should be wrong.

出轴角度：如果出轴向上，那么我们称之为正角度，这种情况下，下压船尾，如果你想象船体被一根穿过重心的硬棒横向支撑，那么这个很容易理解，船尾下沉，船头升水，减少浸水面。如果出轴向下，那么称之为负角度，提升船尾，压头，增加浸水面。虽然，理论上我们可以通过调整出轴角度来纠正船姿，然而中立角度却是最佳选择，最多调整范围在2度以内，如果超过了2度，就证明船体还有其他问题。

Trim tabs: Normally 2 are used on each side of the boat. The outer ones take care of the behavior of the boat on turns, the inner ones of the attitude when traveling in a straight line. We will take care of those from now. Increasing the trim tabs angles - orienting down the adjustable portion - raises the transom, dropping the bow - the boat increases the wet area. Inversely, reducing the trim tabs angle - directing up the adjustable component - lowers the transom and raises the bow, reducing the wet area.
压水板：通常船尾每侧有两个，靠外的负责船体转弯时的姿态，靠内的负责船体直行时的姿态。调整效果：增加压水板角度(向下调整压水板)，将会提升船尾，压低船头，浸水面增加。相反调整，减少压水板角度(向上调整压水板)，降低船尾，提升船头，减少浸水面。
Outer trim tabs act on turns. Remember, adjusting them to rise the transom makes the nose dig on turns, making the turns eventually sharper than desired.

靠外的负责船体转弯时的姿态。调整靠外的压水板来提升转弯时的船尾，从而压头，最终结果是转弯半径小。

Once again, the degree of possible actuation is limited - if correcting the attitude demands more than few degrees of actuation, we must look in another place the solution of the problem.

同样的，调整的角度是有限的。如果调整角度超过了范围，我们必须考虑船体其他部分来解决问题。

Hooks and Rockers: Hook is a concave surface on the bottom of the hull, near the stern, that acts like a big trim tab and raises the transom - lowering the bow and increasing the wet area. Rocker is exactly the opposite - a convex area near the stern, that lowers the transom and raises the bow.
Some manufactures claim that those surfaces are made on purpose on their hulls, to determinate the attitude of the boat on water. I don't like the solution, I prefer to believe that both are defects that must be corrected. The attitude of the boat must be determined by devices that allow adjustments and not by this way.  The correction is very complicate. The rocker must sanded until be level with the bottom of the hull, the hook must be filled with and sanded.
Both corrections are complex and time consuming, reason why I suggest you to avoid a hull with any of those characteristics.
Hook是船底靠近船尾的凹面，它如同一个大的压水板，提升船尾，压低船头，增加浸水面。Rocker是船底靠近船尾的凸面，它降低船尾，抬升船头。
有些厂商声称这些凹面和凸面是故意被设计出来，用来调整船姿。我不喜欢这个说法，我宁愿相信船体是有问题的。船姿是通过可以调整的装置来实现的，而不是通过这种方法。
纠正的方法很复杂。凹面要补灰，凸面要打磨，这是很耗时的，所以我建议你别买这样的船体。

Propellers: Some models of props have as a characteristic to raise the transom, they are the high lift props. Among Octura props they are the ones with no letter on the identification number; the low lift props have a letter on their codes: X or V series belong to this kind. Check if you are using the proper prop and change if necessary.
桨叶：有些桨叶是带有提升船尾的功能的，他们称之为高升力桨。在Octura产品中，这种桨叶是没有标志的。而低升力桨，一般是以X或者V开头。桨叶也可以改变航姿。

Drives: Some drives may have a tendency of raising the transom. Possible corrections are:
o        adjusting the drive angle, making it a little positive;
o        if the drive has a straight and level surface contacting the water, consider rounding this surface on a lathe.
驱动轴：有些驱动轴可以提升船尾，可能的解决方案：
o         调整驱动角度，稍微带些正角度
o        如果驱动带有直角，考虑倒角.

To move the prop far from the transom: extending the prop far from the transom creates an automatic correction for the excessive raising of the bow because every time the bow raises the prop goes deep into water and raises the transom, counter reacting the raising of the bow - again an excessive correction raises another problem - in this case porpoising.
如果让桨叶远离船尾将会自动压头，因为船头抬高的时候，桨叶都会更深的插到水里，进而提升船尾。相反的，如果桨叶距离船尾近，将自动抬头。同样，过多的调整还会产生其他问题，这个例子里面就是跳动。
Other elements that have an influence on the boat attitude on water are the strakes and steps, which are part of the hull design and are not susceptible to correction. If those characteristics are not suitable, choose another hull.
影响船姿的其他因素包括Strakes 和Steps, 他们都是船体本身的设计，并且是不易改变的。如果这些不合适，就换条船吧。

Prop walk: The counter-clockwise rotation of the prop acts like a paddle wheel and drives the stern to the left. Consequently, the bow is deviated to the right; the boat doesn't run in a straight line even with the rudder on a neutral position. Possible corrections are:
o        Sharpen the prop:The sharper, the less the tendency to prop walk, there is no counter effect to this solution;
o        Deviate the strut to the left, to counter react this effect. Again, the angle should be very mild because the deviation to left tends to raise the port side of the boat. Added to the raise caused by torque roll, it can result in an excessive raising and a boat with tendency to chine walk.
o        Adjust the transmitter trim, so the rudder is a few degrees to the left. Again, little correction is advisable because the rudder on this position cause drag and reduces performance.

Prop walk：桨叶逆时针的转动会使船尾向左。结果是船头向右偏，如果船舵是正的，那么船就不会走直线。纠正的方法包括：
o        销尖桨叶，桨叶越尖反扭里就越小
o        把出轴向左偏一个角度，抵消反扭。这个调整量要很小，让不然会导致船体左侧提升。提升过大，就会导致水平左右摇摆。
o        调整船舵，让舵向左偏几度。同样，这种调整会增加船体的阻力降低效率。

Chine Walk: It's a lateral movement, from side to side - the boat looks like walking over water - if the other adjustments were made into the narrow limits allowed, you may try to correct chine walk adjusting the trim tabs. Check which side raises and reduce the trim tab angle at this side and/or increase the angle of the opposite trim tab. Remember that; raising the stern makes the bow down at the same amount - the inverse is also true. So, if the correction implies dropping the port side this may result in an excessive raising of the bow and make the boat unstable. A better solution could be raising the starboard, adjusting the right trim tab. Same is true if correction implies raising the transom of a boat that already has a big wet area: lowering the other side of the transom would be a better solution.

Chine Walk:- 这是种横向运动，从一边到另一边，船体像在水面散步。如果其他调整量都被限制，可以尝试调整压浪板。观察船体的那边船舷高，那么就调低那边的压浪板角度，或者调高相反面的压浪板角度。记住，船尾提升的量和船头下降的量相等，相反亦然。所以，如果纠正量降低了船体左舷，那么将会很高的抬高船头并使船体不稳定。较好的方法是调整左侧压浪板从而提升右舷。同样，如果调整量提升了已经有很大浸水面的船尾，那么降低另外一边的船尾是更好的方法。

Porposing: Up and down movement, when running in a straight line. Could result from a prop too far from the transom, by a too positive strut angle or a too shallow prop. Possible corrections are:
o        Bring the prop near to the transom, 1/2 inch each time, testing after each adjustment;
o        Adjust the strut angle;
o        Lower the strut.
Porposing: 船体跑直线时上下运动，可能是桨叶距离船尾过远，可能是过高的出轴正角，可能是桨叶浸水不够。调整方法：-
o        将桨叶移近船尾，每次调整1.5厘米，测试再调整;
o        调整出轴角
o        调整出轴高度.

twototoo

Torque roll: As a reaction to the engine torque, that turns counter-clockwise, the hull leans to the right - port side raises and starboard goes deep into water. Possible correction are:
o        Mount the strut to the right of the keel (not more than 1/8 inch). So, the lifting force of the prop is applied more at the right, raising the starboard and compensating for the torque roll;
o        Lower the starboard trim tab;
o        Move to the left everything that is not fixed to the hull (battery, fuel tank, etc.)
反扭：发动机扭力的反作用，发动机逆时针转动，船体向右边倾斜。调整方法：
o        出轴向右倾斜（不要多于1/8inch），这样可以增加右边的升力，抵消反扭
o        降低右舷的压浪板;
o        设备左装，调整横向重心，抵消反扭。

Stability on turns: Every boat sideslips and leans on turns. If side slipping/leaning are excessive, impairing the turn negotiation, those are possible corrections:
o        Adjust the external trim tabs, raising the transom and lowering the bow at turns; as a consequence, the hull will tend to make sharp turns and minimize the side slip.
o        Use a bigger rudder and lower it: the bigger and lower rudder tends to raise the transom and minimize the side slip.
o        Lower the CG. Possible correction is lower the engine/tuned pipe.
转弯稳定性；每个船转弯时都有侧滑和向内倾斜的趋势。如果这种趋势过大，将会影响转弯稳定性和通过性。解决办法：
o        调整靠内的压浪板，转弯时提升船尾降低船头。船体将会转弯半径小并且最小化侧滑。
o        使用较大的舵刀并且底装，这样可以提升船尾减少侧滑。
o        降低重心

I hope I could make it clear that there not a magic solution. Correction of a boat attitude demands time and a lot of tests. And remember: the boat is over a seesaw, whenever you do something to a side, a reaction occurs on the opposite side. Some corrections - maybe all - are not a consensus. For instance, using trim tabs for correcting the boat attitude is condemned by Jim Nissen. He say that trim tabs are crutches. And a final word: adjusts for correcting a problem can cause others. Complicate? Sure. But this makes the delights of the hobby.
调船没有什么神奇的办法。调船需要时间和测试。记住：船体就像一个跷跷板，当你在一边调整的时候，另一边会相反变化。并不是错有的调整措施都具有一致性，例如：有人说压浪板就是个拐棍。最后说一下：为了一个问题进行调整，可能会导致其他问题。复杂吧？当然，但这正是爱好的乐趣。

Finally:
最后，我们可以把上面说得总结到下面的图片，有点夸张，但是比较容易理解。但是，记住如果问题让你需要一个很大的矫正量进行调整，那么肯定还有你没有发现的其他问题。
We may put together everything detailed above in a few drawings that concentrate the multitude of available options for adjusting your boat. Naturally, the drawings are exaggerated on purpose, to make the idea clear. If you need so radical adjustments, something is strongly wrong with your boat.

twototoo

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