
English: 
The future of flight shouldn't be things
with propellers and turbines and should
be more like what you see in Star Trek;
with a kind of blue glow and something
that silently glides through the air.
When I got an appointment at University
I thought well, now I've got the
opportunity to explore this
and started looking for physics
that enabled that to happen.
The sort of mechanism that I found
that works was ionising air
and then using electric fields
to accelerate the air.
What we achieved, was the first
ever sustained flight of an aeroplane
that is propelled by
electroaerodynamic propulsion.
And that's also by many definitions 
the first ever solid-state flight,
meaning no moving parts.
Well the idea is - is kind of - it dates
back until at least the 1920s.

Chinese: 
未来飞行应该摆脱推进器和涡轮
而是像《星际迷航》中看到的那样 伴随一道蓝光
飞机一掠而过
当我得到一份教职工作后
我就想我终于有机会好好探索一番了
我开始寻找能实现这种飞行的物理机制
我发现了一种有效机制是电离空气
利用电场加速空气
我们成功获得了第一架依靠电空气动力推进的飞机
并完成了首次持续飞行
从很多方面来看 它也是首架固体推进飞机
即没有活动部件
这种设计理念至少可以追溯至上世纪20年代

English: 
Where an eccentric inventor at the time started
experimenting with high high voltage electrodes.
And thought he had discovered anti-gravity,
which of course was not the case.
But that set some of the initial
groundwork on mechanisms for creating
what's called an ionic wind in the
atmosphere, by having high-voltage
electrodes ionising air and then
accelerating the ionised air.
So what we did for this design is to
try and stick to something that looks
somewhat like a  conventional aircraft.
But under the wing rather
 than conventional engines
it has a series of electrodes. And those consist
of an array of very thin wires at the front,
and then an array of aerofoils at the back.
Now those thin wires at the front are set at
a very high voltage - plus 20,000 volts
and that constitutes the source of ions - 
this is ionised nitrogen from the atmosphere.
Now the the aerofoils at the back there 
set at minus 20,000 volts
and so that creates an electric field.

Chinese: 
当时一位古怪的发明家开始利用高压电极做实验
自认为发现了反重力 当然事实并非如此
但是这些初步工作
为后来在大气中制造离子风奠定了基础
即通过高压电极电离空气 然后对电离空气进行加速
我们在设计中尝试采用
与传统飞行器相仿的外形
但是机翼下面并没有传统的发动机
而是一系列电极 前端由极细的电线阵列组成
后端是翼型阵列
将前端的细电线电压设置到非常高 超过2万伏
就构成了离子源 这是大气中的氮离子
现在后端的空气电压设置为-2万伏
由此形成一个电场

Chinese: 
离子从正极流向负极
途中不断与中性空气分子发生碰撞
由此形成的风流向飞机尾部
这基本就是这架飞机的飞行方式
飞行持续了10秒左右 一共飞了约60米 非常短
这受限于我们所能找到的体育馆的大小
我们缺资金缺时间 只想尽快把事情做出来
这是我们手头仅有的资源
所以我们直接问负责人能不能使用体育馆
他们要求我们制定一个非常长且详细的安全管理计划
之后我们才得以展开实验
许多次尝试都失败了 因为各种事情出错
比如结构性故障 动力电子设备故障
所以我们做了很多很多次尝试 第一次成功
也不是持续飞行
约借助了一半的动力 所以是一次动力滑翔
直到这时我们仍不能百分百确定是否真的能成功
但是在那之后我们知道
距离成功飞行只有咫尺之遥

English: 
So the ions go from the
positive to the negative
colliding all the way with neutral air molecules
and creating this wind 
that goes behind the  plane.
And that's essentially how it flies.
The flight was about sixty meters long, 
something like ten seconds - so quite short.
It was constrained by the size of the
gym that we found to fly it in.
Lacking infinite money in time and just wanting
to do things as quickly as possible
that was what was on hand
and so we just asked the facilities manager
if they would let us use the gym,
they forced us to create a very long and 
detailed safety management plan
but then we were
able to go ahead.
Many attempts failed because
of various things going wrong
like structural failures,
the power electronics frying itself
so there are many many first days,
but the first day that it actually worked
wasn't a sustained flight it was about 
50% power, so it was a power glide.
Until that occurred we still didn't know 
100% whether this was really achievable.
But after that point we knew that
we were then within touching
distance of successful flights.

English: 
And the first sustained flights
followed quite soon after, which were...
which were pretty exciting.
It's probably the first solid-state flight
of a heavier-than-air vehicle
and I think that is, has the potential to be
a step that is very interesting.
Of course we don't yet
know whether it will be
practically useful and widely used
and obviously I hope it will be
and have an expectation -
there are a number of applications.
There are definitely some limits,
so one of the limits is
the breakdown voltage of air
and that varies as a function of altitude.
And we've worked out theoretically what the
limits are to the thrust density
which is the amount of
thrust force per unit area that's producible.
Now what that suggests 
is that in the nearer term,
it will be easier to create smaller
vehicles like drones for example.
I think the near-term advantage
is probably in noise
especially if you think that
perhaps in ten years we might have urban
areas that are filled with drones doing
things like monitoring traffic,
monitoring air pollution
or many other services we're yet to imagine.

Chinese: 
之后不久就实现了首次持续飞行
非常令人兴奋
那可能是比空气重的固体推进飞机的首次飞行
我认为它代表了前景可观的一步
当然我们还不知道它是否具有实用意义 显然我希望如此
并且期望它能得到大量应用
局限肯定存在
其中之一就是空气的击穿电压
它会随高度变化
我们从理论上弄清楚了
推力密度的范围 即单位面积可产生的推力
由此可知 在不远的将来
制造无人机等小型交通工具将变得更简单
我认为近期优势体现在噪音方面
试想在十年内
城市地区可能充满各种无人机
监测交通流量 监测空气污染或者
执行其它我们尚无法想象的任务

English: 
And drones today are
quite noisy and irritating.
Now we wouldn't want our urban environments
to be polluted by all this noise,
so developing a way of propelling drones
that's silent or near silent would be
advantageous in that context.
In many ways it's much easier to make
progress now than it was in the past.
I mean if you look at this
wonderful aircraft behind us
which was the first ever
transatlantic flight - about 1919
I mean people were risking their lives
to make that kind of progress.
Today we're not risking our lives
we're able to test things using
a remote control,
without having to have pilots on board test vehicles.
That means the vehicles can be much smaller
which enables us to build them and test
them with less resources.
In terms of how this fits in
I don't know whether you'll see
large aircraft carrying people anytime soon.
But obviously I'd be very
excited if that was the case.

Chinese: 
目前的无人机非常嘈杂烦人
我们一定不希望城市环境被这种噪音污染
因此开发一种可以无声或近乎无声地推进无人机的方法
将非常有益
从很多方面来看 现在要做的工作比以前容易多了
我的意思是如果你看一下我们身后这架令人惊叹的飞机
它在1919年完成了首次跨大西洋飞行
当时的人冒着生命危险换取了这种进步
今天的我们不用冒着生命危险
就能通过远程遥控进行测试
不需要飞行员参与试飞
这意味着飞机体积可以大幅缩小
让它们的制造和测试成本都更低
至于它的实际应用
我不知道是否很快会出现能载人的大飞机
如果能够成真 我一定会非常兴奋
