[科技前沿]电动车之后，电动飞机问世

First electric cars, now electric planes

GM (MTLQQ) has earned high praise this summer – and deservedly so – for its announcement that the forthcoming Chevy Volt electric car will get as much as much as 230 miles per gallon for in-town driving.

But while Detroit was stealing headlines on the ground, a little-known Chinese company was doing something even more incredible in the skies.

At the OshKosh AirVenture show a few weeks ago, Beijing startup Yuneec International took the wraps off the world’s first commercially produced electric aircraft, the E430.

Powered by lithium polymer batteries, weighing close to a thousand pounds, and sipping about $2.50 worth of electricity per hour of flight, the E430 has completed more than 20 hours in test runs during the last couple months, including one in Camarillo, CA, that can be seen here.

Little more has been revealed about the E430, other than some technical specifications and that it can operate for up to three hours without a charge.

Today: adding electricity-powered systems

And while the E430 may be the aircraft equivalent of an auto show concept-car, there’s a good deal of progress being made in the advancement of electrical aeronautics on the whole. “What’s going on with modern aircraft is a revolution, whether you’re thinking about commercial or military aircraft,” says Bob Smith, VP of advanced technology at Honeywell Aerospace, a unit of Honeywell (HON).

Smith doesn't mean fully electric-powered aircraft – at least not yet. In aeronautic jargon, he’s talking about developing More Electric Architecture (MEA). Enabled by much larger and more sophisticated next-gen aircraft and more efficient generators, Honeywell is replacing the pneumatic and hydraulic power transference systems of with new electric versions.

“If you look at how much power a Boeing 777 generates, it’s on the order of 200-300 kilowatts. If you look at the 787, a next-gen aircraft, it’s 1.5 megawats,” he says. “That’s a massive change, because the generator technology has improved so much.”

Moving power around aircraft has always been cumbersome. In last-gen aircraft, high-pressure gas is taken from the engine and transported through bleed valves to the auxiliary power system, which controls air-conditioning, for example. This is a massively inefficient process due to the energy required to heat and cool the gases and because of the weight of the systems. “If you can put a more efficient generator in there, you have a power station as opposed to a boiling room,” says Smith.

Electrical systems are now being used to power reverse-thrusters – air brakes, essentially - in aircraft like the A380 – and for de-icing wings.

The upside: gains in fuel efficiencies

But two of the greatest benefits electrical systems provide are simplicity and merely lightening the load. Eliminating hydraulic systems reduces the complexity of repairing leaks and eliminating hundreds of pounds of tubing.

This can lead to as much as 30% gains in fuel consumption. For military aircraft, such a system is revolutionary. In the F35 Joint Strike Fighter, Honeywell’s system carved 1,000 pounds off the weight and 11 inches off the length of the plane.

Does Honeywell have its own E430 read for prime time? Not quite, but Smith suggests the real near-term potential for fully electric aircaft comes in the form of unmanned drones. Think about light-weight drones that travel constantly, their electric systems being continually replenished by advanced technologies like super capacitors, fuel cell systems and solar power.

“Once you have large power-generating systems, you have the capability of moving the power around a lot of different ways,” says Smith. “Then things get pretty interesting, allowing you to get into very long surveillance periods.”

通用汽车(GM)今夏获得盛赞，这一点是实至名归的，因为公司宣布即将推出雪佛兰Volt电动车，该车在城市路况下可实现相当于230英里每加仑的燃油经济性。当通用汽车在地面上的新举动抢占媒体头条之时，一家不太知名的中国公司正在天空中进行更加不可思议的创造。

在几周前举办的奥什科什航空展中，北京新创企业Yuneec国际公司展示了世界上第一架商用电动飞机--E430。

E430以锂聚合物电池为动力，机身重近1000磅，飞行中每小时消耗价值2.5美元的电。在过去几个月里，E430完成了总计超过20小时的多次试飞，包括在美国加州卡马里罗市的一次试飞。

关于E430的信息，只披露了一些技术规格，以及它每次充电后连续操作时间长达3小时。

今日：增添电力动力系统

E430飞机的出现就像车展中的概念车。与此同时，电子航空领域整体上也取得了很大的进展。霍尼韦尔（Honeywell）旗下霍尼韦尔航空公司的新技术副总裁鲍勃•史密斯(Bob Smith)表示：“无论是商用机还是军用机，当代飞机正在经历一场革命。”

史密斯所指的并不是完全以电力为动力的飞机，这一点至少在目前还无法实现。在航空领域的行话里，史密斯指的是开发更加电气化的框架。受到更大更复杂的下一代飞机和更高性能的发动机的推动，霍尼韦尔正在以新的电子系统替换气液动力传输系统。

史密斯表示：“波音777所产生的动力在200到300千瓦之间。而下一代飞机波音787，就增加到了1.5兆瓦。这是一个重大改变，因为发动机技术已得到很大发展。”

飞机的动力传输设备向来比较笨重。举个例子，在上一代飞机中，引擎中的高压气通过排除阀到达辅助动力系统，该系统控制着空调设备。这是一个效率极低的流程，因为加热或冷却气体需要能量，并且这种系统也很重。史密斯表示：“如果能够装备更加高效的发动机，你将会拥有一个发电站而不是一个沸腾室。”

电子系统现在应用于A380这样的飞机中的逆功率推进器，主要是气闸，以及为机翼除冰。

有利的一面：节约能耗

但是电子系统提供的两个最重要的好处是简化系统和减轻重量。停用液压系统避免了修复泄漏的复杂局面，并且省下了重达数百磅的管材。

这种做法节省了30%的燃料消耗。对于军用机来说，这一系统是革命性的。在F35联合攻击战斗机上，霍尼韦尔的这一系统帮助机身减轻1000磅，缩短11英寸。

霍尼韦尔是否拥有自己的E430，可以在黄金时段大加宣传呢？现在还没有。但是史密斯表示，短期内有可能真正实现无人驾驶飞机的完全电动化。想想长时间飞行的轻型飞机，它们的电子系统持续得到先进技术的补充，比如超级电容器、燃料电池系统以及太阳能供电。

史密斯表示：“一旦有了大型发电系统，你就有能力用多种不同的方法进行动力传输。这将使事情变得非常有趣，让你可以进行长时间的监测。”