Embed pageUse this link to embed the video into your website.
You FlashPlayer needs an update ti display this content.
Biologists know: No animal swims as quickly and enduringly as the great white shark. This predator achieves his tremendous speed thanks to a special skin structure: his scales sport small grooves, also known as riblets, which reduce frictional resistance in the water. Nowadays, the effect is also exploited by competitive swimmers such as Michael Terhorst. In the water the budding engineer wears a special swimsuit made of artificial sharkskin and with it can reduce his time over the distance of a hundred meters by one second. Does the skin demonstrate the same effect when applied to vehicles, such as airplanes for instance? Terhorst finds out about a research project at the RWTH Aachen. Here engineers from various disciplines investigate other applications the riblets might be exploited for.
Riblets against frictionTo date they are mainly used in high-performance sports: artificial sharkskins. They reduce drag and therefore save energy. Is this principle transferable to other applications, such as on aircraft?
Miniature TempestHow do riblets work? The grooves demonstrate their friction reducing properties on a model airplane. In practice, however, artificial sharkskin has its own particular intricacies.
Fine grooves for stable bladesCan the sharkskin grooves be directly imprinted onto metal? This is how the researchers from Aachen want to drastically improve the energy efficiency of aircraft turbines.
The perfect rollerA particularly difficult problem: the researchers need an extra hard roller – which needs to simultaneously treat the material gently.
Projectiles in the airOn an aircraft the riblets will have to withstand extreme stresses: At a travelling speed of 800 kilometers per hour even raindrops could create substantial damage. Therefore the riblets have to undergo a practical test.
Think big!Premiere in Aachen: for the first time, engineers roll their shark riblets onto a real turbine blade. Will it be able to cope with the extreme stresses it will be subjected to?
Well wired Almost like a sewing machine: a new roller uses fine steel wires, in order to produce riblets. It imprints soft materials such as aluminium and could thus possibly be of help in creating sharkskin for trains, for example.
Test on the computerThe first setback: the new roller for the aluminium sheet doesn’t yet work exactly enough. Can computer simulations improve the results?
Research for the futureThe simulations at the computer have provided a crucial clue: now the researchers from Aachen can roll a perfect riblet pattern onto aluminium. An important step for application in transport.
Do you have questions or comments concerning this
project? We are looking forward to your contribution:
No questions and answers available, yet.
*) The Project
Sharks are lightening fast hunters – thanks to a special riblet structure on their scales, they glide effortlessly through the water. Björn Feldhaus from Aachen wants to apply these so-called riblets to the technical surfaces of airplanes. With their help it could be possible to reduce frictional resistance, hence reducing fuel consumption and carbon dioxide emissions.
Mechanical engineer Björn Feldhaus works as a research assistant for the Laboratory for Machine Tools at the Technischen Hochschule Aachen. As a member of a research team led by Professor Fritz Klocke he wants to make the riblet structure of shark skin available for application to external surfaces and turbines of airplanes in order to minimize their energy consumption.
Engineer Björn Feldhaus from Aachen and his team want to apply the riblet structure of shark skin to technical surfaces.