直升机物理系列 - #2 操纵控制 - 每天变聪明一点 46：英语精读讲义

All right,

好吧，

this is totally easy once you understand the physics. 語法

一旦懂了物理原理，这就非常简单了。

Watch this,

看这个，

left,

左，

yep,

对，

right, go back to the right.

右，回到右边。

It's easy!

很简单！

You see it flip?

看到它翻转了吗？

One, two,

一、二，

yeah.

耶。

Awesome.

太棒了。

So,

那么，

as a kid,

小时候，

I spent many an hour in a book about the drawings of Leonardo da Vinci. 語法

我花了很多时间看一本关于列奥纳多·达·芬奇画作的书。

In particular, 表達脈絡

特别是，

his flying machines.

他的飞行器。

Check out this medieval helicopter. 短語動詞

看看这架中世纪的直升机。

It looks like it would work, 語法

看起来它能飞，

but you can't really judge a book by its cover 習語

但你不能只看表面，

because there's no way to provide counter-torque to the body of the aircraft. 講解

因为没有办法为飞行器机身提供反扭矩。

Modern-day helicopters do this

现代直升机是怎么做的呢，

by providing a counter-torque rotor on a boom,

通过在尾梁上提供一个反扭矩旋翼，

a tail rotor.

即尾桨。

This works by stopping the rotation of the helicopter,

这可以阻止直升机旋转，

but here's what you haven't thought about. 表達脈絡

但有些事你还没考虑到。

You are,

毕竟，

after all, 表達脈絡

你是

applying a force to a free-floating body, 用詞

在对一个自由漂浮的物体施加力，

which means that body wants to drift. 表達脈絡

这意味着该物体会发生漂移。

So,

那么，

how does a helicopter keep from drifting? 語法

直升机是如何防止漂移的呢？

We're gonna take a journey.

我们将开启一段旅程。

We're gonna go from a top-level knowledge of how helicopters work 語法

我们将从直升机工作原理的基础知识

to a really deep understanding.

深入到非常透彻的理解。

How you doing,

你好，

Mr. Ledbetter?

Ledbetter 先生？

Hi, I'm Richard Ledbetter.

嗨，我是 Richard Ledbetter。

I'm a docent at the National Air and Space Museum. 文化背景

我是国家航空航天博物馆的讲解员。

All right.

好的。

So,

那么，

what do you have to show us today about how helicopters work?

今天关于直升机的工作原理，您要给我们展示些什么？

Well,

嗯，

I guess what we're gonna talk about is kinda the main rotor system on a conventional helicopter, 表達脈絡

我想我们要谈论的差不多是传统直升机的主旋翼系统，

and the main rotor system basically provides both the lift and the control for the helicopter. 語法

而主旋翼系统基本上为直升机提供升力和控制。

And how we control the helicopter 語法

我们控制直升机的方法

is by varying the pitch at each of the rotor blades. 用詞

就是改变每个旋翼桨叶的桨距。

So,

那么，

how do you vary the pitch on a helicopter when it's rotating?

当直升机旋转时，你是如何改变桨距的呢？

When the blades are rotating?

当桨叶旋转时？

We use on most helicopters,

我们在大多数直升机上使用，

we use something called a swashplate.

使用一种叫做十字盘的东西。

Okay.

好的。

And essentially what a swashplate does is it converts non-rotating to rotating control motion. 講解

十字盘的本质作用是将非旋转的控制动作转化为旋转的控制动作。

We have two kinds of control for the helicopter,

我们的直升机有两种控制方式，

and for cyclic inputs,

对于周期变距输入，

what happens is

会发生的情况是

that swashplate will just simply rotate forward or rotate aft,

十字盘只会简单地向前或向后倾斜，

and that changes the input to each of the rotor blades.

这就改变了对每个旋翼桨叶的输入。

But for collective pitch,

但对于总距，

what will happen is that swashplate will actually move up or down,

会发生的是，十字盘实际上会上下移动，

that will actually change the pitch in both of those rotor blades

这实际上会改变那两个旋翼桨叶的桨距

at exactly the same time.

并且是完全同时改变。

Oh,

哦，

okay.

好的。

I just learned something.

我刚学到了新东西。

So,

所以，

in summary, 表達脈絡

总结一下，

there's three types of control.

有三种类型的控制。

There's collective pitch, 用詞

有总距，

there is cyclic pitch,

有周期变距，

and then there's anti-torque.

然后是反扭矩。

Of course,

当然，

anti-torque is the rotor system on the back.

反扭矩就是后面的尾桨系统。

So,

那么，

let's start with collective,

让我们从总距开始，

Carl.

Carl。

So,

那么，

what is this magical device right here?

这里这个神奇的装置是什么？

This is the swashplate,

这是十字盘，

and this is the source of all control for any helicopter.

它是任何直升机所有控制的来源。

Uh any direction the swashplate moves,

呃，无论十字盘朝哪个方向移动，

for the most part, 短語搭配

在大多数情况下，

the helicopter follows.

直升机就会跟着移动。

So,

所以，

the collective is where you change the pitch of both blades

总距就是你改变两个桨叶桨距的地方

either up or down, 語法

向上或向下，

and that pulls the helicopter up or down.

这就拉动直升机上升或下降。

You do not control the

你并不通过

altitude of the helicopter by the speed of the blades.

桨叶的转速来控制直升机的高度。

That stays the same.

转速保持不变。

It's translated up or down,

它（十字盘）上下平移，

and that controls how much of a bite of air the rotors take. 習語

这控制了旋翼“咬合”空气的量。

Is that correct?

对吗？

That is. Yep. absolutely.

是的。没错。绝对正确。

And that'll actually make the helicopter either go up or down.

这实际上会使直升机上升或下降。

Or if it's upside down,

或者如果它是倒飞的，

it's backwards.

那就是反过来的。

Oh,

哦，

yeah,

是的，

cuz it's upside down, 用詞

因为它是倒飞的，

cuz I'm a helicopter genius.

因为我是直升机天才。

The tail rotor,

尾桨，

just like the main blades,

就像主旋翼桨叶一样，

never changes speed.

从不改变转速。

So,

所以，

in order to control the thrust, 語法

为了控制推力，

we change the pitch on the blades,

我们改变桨叶的桨距，

so it can act push or pull in both directions.

这样它就能在两个方向上产生推或拉的作用。

And the reason it does that,

而它这样做的原因，

it's basically a reaction torque to what's going on up here. 講解

基本上是对上面所发生情况的反应扭矩。

The blades are putting a torque into the body,

桨叶正在向机身施加扭矩，

is that correct?

对吗？

Yep.

对的。

The act of spinning the blades makes the helicopter want to go the opposite direction. 語法

旋转桨叶的动作会使直升机想要朝相反的方向转动。

Makes sense.

有道理。

Can you show me what cyclic pitch looks like now? 語法

你现在能给我展示一下周期变距是什么样子的吗？

Cyclic pitch is where the swashplate tilts

周期变距是十字盘倾斜

and through the linkage controls the pitch of the blades

并通过连杆控制桨叶的桨距，

and changes it every revolution 用詞

在每一圈旋转中都改变桨距

to control the pitch and roll of the helicopter. 用詞

从而控制直升机的俯仰和横滚。

Give me cyclic pitch in this direction.

给我演示一下这个方向的周期变距。

Okay,

好的，

but then if I rotate it,

但如果我转动它，

it'll change as it goes around,

它在旋转时就会发生改变，

correct?

对吗？

It does change.

确实会改变。

So,

那么，

so that linkage rides on the swashplate

所以那个连杆连在十字盘上，

and then pushes up on the side of the blade,

然后在桨叶的侧面向上推，

and then that in turn changes the blade depending on where it is in the rotation of the rotor shaft, 講解

接着这又反过来根据桨叶在旋翼轴旋转中的位置来改变桨叶，

right?

对吗？

Correct.

正确。

All right.

好的。

And so,

那么，

what does that do for ya?

那对你有什么用呢？

That uh lets me flip it any way I want to. 語法

那让我想怎么翻转就怎么翻转。

That lets me do wizardry.

那让我能施展魔法。

Okay,

好的，

now you speak helicopter. 習語

现在你懂直升机的语言了。

And for the next few videos,

在接下来的几个视频里，

prepare for your mind to be blown, 習語

准备好大开眼界吧，

but we're going to be using these fundamental terms.

但我们会使用这些基本术语。

So,

所以，

get ready.

准备好。

Go ahead and

现在就

subscribe so you can see this video series.

订阅吧，这样你就能看到这个视频系列了。

It's worth it.

绝对值得。