TO LOWER the fuel consumption of airplanes and ships, it is necessary to reduce their flow resistance, or drag.
An innovative paint system makes this possible. This not only lowers costs, it also reduces CO emissions.
The inspiration – and model – for the paint’s structure comes from nature: The scales of fast-swimming sharks have evolved in a manner that significantly diminishes drag, or their resistance to the flow of currents.
The idea that sharkskin, which is rough to the touch, might in fact offer a way of reducing surface drag on aircraft and ships has been around for some time.
The challenge was to apply this to a paint that could withstand the extreme demands of aviation especially where temperature fluctuations of -55 to +70 degrees Celsius are experienced, together with intensive UV radiation and high speeds.
However, German scientists have created a coating system that not only reduces aerodynamic drag, but also the associated manufacturing technology.
The paint involves of a sophisticated formulation. An integral part of the recipe is the nanoparticles, which ensure that the paint withstands UV radiation, temperature change and mechanical loads, on an enduring basis.
It is claimed that, when applied to every aircraft every year throughout the world, the paint could save a massive 4.48million tonnes of fuel.
The new coating also applies to ships.
The German scientists have been able to reduce wall friction by more than 5% in a test with a ship construction testing facility.
Extrapolated over one year, that means a potential savings of 2,000 tons of fuel for a large container ship alone.
A major challenge is how to deal with the algae, mussels and barnacles that commonly attach to the hull of a ship, even when treated with antifouling paint.
One solution is to structure paint in such a way that fouling organisms cannot get a firm grasp and are simply washed away at high speeds, for example. The second option aims at integrating an anti-fouling element.
Irrespective of the fuel savings, there are even more interesting applications – notably windfarms.
Here too, air resistance has a negative effect on the rotor blades. The new paint would improve the degree of efficiency of the systems – and thus the energy gain, say the scientists.