AirToob Lightning

Tags  →  engineering

Nuenen, a city in the Netherlands, has a new extraordinary attraction – a dreamy solar-powered bicycle path that glows in the dark. The path, created by Dutch designer Daan Roosegaarde, looks just like a river of stars, fallen down from Van Gogh’s “Starry Night.” And it is, in fact, inspired by the great artist, who lived in Nuenen from 1883 to 1885.”

Thanks to my younger daughter for this find!

The other work of artist and innovator Daan Roosegaarde is well worth checking out - click the panel below for an example.

It seems that all over the world, inventive people are rethinking the possibilities of our roads - for another example, see my post on Solar Roadways.

(Latest update to this post: 5th January 2017 - the URL for this post has changed and is now here)

Some time ago, Julie and Scott Brusaw grabbed the imagination of several million people, with an invention that may eventually benefit the lives of hundreds of times that number: a modular system of intelligent solar paving slabs made of non-slip, highly durable glass, with many applications.

Apart from generating electricity, these paving slabs can provide variable signage or illumination from high intensity LEDs, keep road surfaces free of snow or ice, and perform a variety of other useful functions.

These smart slabs will also act as local components of the Smart Grid.

Click the graphic, or go here, for more information from my web site.

(Original post: July 7th, 2010)

This hour-long documentary from the BBC marks the inauguration of the Boeing 787 Dreamliner powered by Rolls-Royce Trent 1000 engines, arguably the most advanced engines in the world today.

A turbofan engine (top half of graphic) is simple (hence reliable) in concept, but its engineering is about as far from simple as you can get.

Most of the thrust actually comes from propellers - fan blades - which are mounted inside an outer enclosure. The fan blades are driven by a turbojet engine, around which flows the cold air from the fan.

This engine has 20 fan blades, which together pump over a ton of air each second. Each one costs about the same as a typical family car, and has to exert a force equivalent to lifting 13 double-decker buses.

When fitted inside their shroud, the blades have an end-clearance of less than 1mm.

Each blade is precision-made from a 3-layer titanium sandwich, in a secret process that involves inflating the blade to get this super-strong structure.

Each blade is then tapped with a mallet and its exact natural resonance electronically measured. The order in which the blades are fitted around the shaft depends on matching these resonances for perfect balance.

This is where the business happens. The hot air from the combustion chamber, compressed by the blades towards the front of the turbojet, hits 96 turbine blades, which have to operate in a "fairly harsh environment". At maximum thrust they turn at 10,000 RPM, moving at 800 MPH, surrounded by a temperature of 1700 degrees - which is 300 degrees above the melting point of the alloy.

Each turbine blade feels a force of some 18 tons. Normal metal is crystalline in nature - under a microscope it is reminiscent of a granite kitchen worktop - and isn't strong enough for this task. Rolls-Royce has developed a process, the non-secret parts of which are shown in this film, for casting each blade as a single super-high-strength crystal.

The "fir tree" base of one blade, which will be machined to 7 microns - and keep that tolerance after being stretched by 18 tons of force.

The upper part of the blade, showing the cooling channels that stop the alloy melting, by removing enough heat to boil twenty kettles in each second.

The prototype engine has to pass two years of tests before it is certified. One of these is pumping 30,000 gallons per hour of water through the engine, during which it must work normally.

(Twin engined aircraft crossing the Atlantic have to be certified for ETOPS, which officially stands for Extended Twin OPerationS. Unofficially, although the film doesn't say this, it stands for "Engines Turning Or Passengers Swimming". An ETOPS-certified aircraft must have ultra-reliable engines, and be able to fly perfectly well on only one engine.)

The most spectacular test destroys a very expensive engine. A fan blade is detached by an explosive charge with the engine running at full thrust, resulting in a force of unbelievable magnitude...

...and an eye-blink later, the engine is ruined but everything has been contained within the super-tough outer shell.

While the technology is truly awesome, the documentary also focuses on the people that make it all happen. Rolls-Royce cars are now made by BMW, but the aero-engine business is still the old Rolls-Royce. From people who deal with logistics to people who carry out precision machining, from metallurgy specialists to people who check and test every aspect of every process, these are folk for whom mistakes are simply not an option.

Even what looks like a very large call-centre turns out to be a room-full of specialists monitoring, 24/7 in real time, the performance of engines powering hundreds of aircraft flying all over the world.

The style of the documentary occasionally set my teeth on edge, but the content is well worth watching.

If you liked this, the Rolls-Royce Merlin engine is featured here:

[Florida's least-known major attraction: Fantasy of Flight]

and if you would like to explore the world from your PC:

[My "Flight Simulator" page]