Making trains that will fly
Japanese engineers are developing low-friction trains that will lift off the track, using only a quarter of the power required for magnetically levitated (maglev) trains.
The team at Tohoku University Institute of Fluid Science in Sendai is testing the use of the “wing-in-ground” (WIG) effect in which a high-pressure buffer of air forms underneath flying objects as they approach the ground. The absence of friction and wind resistance on a train would mean that little power would be required to maintain forward movement.
The researchers have built the Aerotrain, a 8.1m model with two pairs of wings both fore and aft, each with stabilising units. Without a motor, it is pushed by a lorry along a flat track with retaining walls alongside it. So far in testing, the model has lifted off after reaching 50km per hour and flies between five and 10cm above the ground.
Yasuaki Kohama heads the research team and has studied with Russian engineers who discovered the WIG effect on ships. He believes the method will be more efficient with trains and hopes that eventually the Aerotrain will be powered by energy sources such as solar panels on the tops of track walls or wind turbines.
The testing now is aimed at reducing the speed at which the model lifts off the ground. By keeping the amount of time that the train is on the track to a minimum, they will be able to reduce friction and therefore energy consumption and pollution. The team's goal is to reduce emissions to 3.6 grams of carbon dioxide per person per kilometre, compared to the maglev trains which emit 12.2 grams.
To do this, Kohama's team are building a new model with three pairs of wings and two pairs of propellers so it can reach speeds of 150km per hour. The next step will be a six-passenger train that will travel at 300km per hour and finally, by 2020, a 335-passenger train that will reach 500km per hour.
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