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为什么鸟类没有飞机的垂翼?

Why Don't Birds Have Vertical Tails Like Airplanes?

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我不知道你有没有注意到
I don’t know if you’ve noticed,
可大自然真有那么点儿令人敬畏
but nature is kind of awesome.
这也是我们诸多科技的发明灵感来源于自然的原因
That’s why so much of our technology is inspired by it,
从模仿昆虫做出的胶粘剂到模仿鸟类而设计的早期机翼 都证实了这一点
from adhesives modeled after insects to early plane wings based on birds.
但是我们模仿自然不代表我们就能做到极致
But just because we try to mimic nature doesn’t mean we can do it perfectly,
鸟类和飞机就是很好的例子 可以说明我们的局限性
and birds and airplanes are a pretty good example of our limits.
大多数飞机都采用垂直尾翼
Take the vertical tails on most airplanes.
我们用它们来保证我们巨大的金属装置飞在空中且运行正常
We use them to keep our giant,metal contraptions in the air and going the right way
但是鸟类不必如此就能飞行自如
— but birds get by fine without them.
那是因为在飞行方面 鸟类比我们擅长得多
That’s because they’re just way better at flying than we are,
大多数情况下
and for the most part,
我们不能持久飞翔
we can’t keep up.
飞机的各个部件协同工作
The parts of an airplane all work together
以保证飞机在空中朝着正确的方向飞行
to keep the plane in the sky and facing the right direction.
同时由于各种不可见的空气流
But thanks to all kinds of invisible air currents,
一切就并非你从靠窗玻璃看见的那么简单
that isn’t as simple as it looks from your window seat.
垂直机翼主要的功能是稳定偏航运动
The vertical tail’s main job is to stabilize something called yaw.
偏航可测定飞行中相对于风向偏左或偏右的程度
Yaw measures how much the plane is pointed to the left or right of the wind
尤其是相对气流 它是由飞机急速上升
specifically,the relative wind, which is created by the plane zooming
以数百公里的时速穿越大气层而引起的
through the atmosphere at hundreds of kilometers an hour.
偏航会在转弯或不稳定气流等诸多情形中发生变化
Yaw can change in lots of situations, like during turns or in unsteady air.
如果出现这种情况 偶尔会引发侧滑现象
And when it does, it occasionally leads to a condition called sideslip.
此即飞机虽有偏航
This is where the plane has yawed,
却不至于彻底改变航向
but it hasn’t completely changed its direction.
相反地 它基本上仍然沿着
Instead, it’s still mostly moving
既定方向飞行 只是角度有些跑偏
in the direction it was, only at a funny angle.
有点像跑车转弯处漂移 当然啦
Kind of like a sports car drifting around a turn. Normally,
这会导致效率受到一点点影响
this just leads to a little inefficiency.
但如果不加以矫正 侧滑就会达到失控的程度
But if it’s not corrected, sideslip can get out of hand.
如果飞机偏航运动过大
If the plane yaws too much,
它就会影响机翼的空气流动状况
it starts to affect how the air flows over the wings.
如果过多的气流与机翼平行而非垂直
And if too much air flows parallel to the wings instead of perpendicular,
飞机就会失去升力
the plane can lose lift.
升力决定并保证飞机可以翱翔天际
Which, is kind of important for keeping it in the sky!
这就是垂翼被引入的原因
That’s where the vertical tail comes in.
你看 当飞机开始侧滑
See, as the plane starts to sideslip,
一边的尾翼将会遭遇
the side of the tail will start to face into the
相对气流并和其呈类垂直关系
relative wind and become more perpendicular to it.
而当风推动尾翼表面时
And as the wind pushes on the tail surface,
它将会产生一种极强的推力
it creates a force that ultimately nudges
使得飞机重新回到初始方向
the whole plane back to face its original direction.
然而鸟类就不需要担忧这些
Birds,meanwhile, don’t have to deal with all this
因为它们比我们擅于飞翔得多
because they’re way better at flying than we are.
究其原因 在过去的数百万年它们都在飞翔
Which makes sense, considering they’ve had millions of years to work on it.
它们不需要垂翼保持稳定
They don’t need vertical tails for stability
因为它们一直在根据翅膀的形状和角度
because they’re constantly making fast,
做着迅速 细微的调整
tiny adjustments to the shape and angle of their wings,
这样可以使它们避免侧滑反应
which lets them avoid sideslip.
目前 这还无法被轻易应用到飞机上
Right now, that’s just not something we can practically or easily do with airplanes,
尤其是给客机
especially passenger jets.
但是即便这样还是有一些飞机
And even though there have been some planes
没有垂翼 比如B-2隐形轰炸机
without vertical tails — like the B-2 stealth bomber
它们面临许多稳定性挑战
— they come with plenty of stability challenges.
工程师努力克服困难
Engineers are definitely working on it,
但看起来大自然现还是占了上风
but it looks like nature has one-upped us for now.
当然还有一个方面 工程师并没有被自然占到先机
One place nature doesn’t have a leg up on engineers,
就是保护您的网上信息
though, is protecting your information online.
我的意思是很明显在NordVPN的工程师的努力下
I mean, obviously. Thanks to the engineers at NordVPN,
您可以设置虚拟专用网络
you can set up a Virtual Private Network,
即使在未保护WI-FI中 也能确保您的敏感信息安全无虞
to keep your sensitive information safe even when you’re on an unprotected Wi-Fi network.
无论是您在线订购鸟类玩具还是订机票
Whether you’re online ordering a bird toy or a plane ticket,
您都希望您的私人信息保持安全
you want your private informationto stay safe.
通过虚拟私有网络
With a Virtual Private Network,
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your information is encrypted and sent via one of NordVPNs
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NordVPN has nearly 5,000 super fast servers in 62 countries
并且这个数量还在持续增加 严格来说
and they’re always adding more. Seriously,
就在我们播出此视频时它们可能已经超过5000台了
they might have gotten to over 5,000 since we filmed this episode.
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[结尾乐]
[OUTRO♩]

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视频概述

人类飞机不如鸟?这究竟是怎么回事?速看!

听录译者

收集自网络

翻译译者

盗墓狗

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审核员 DL

视频来源

https://www.youtube.com/watch?v=sLCiDObJY0s

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