Turbulence research finding 'could save billions in energy costs'
on 19/08/2013 10:57:44
Ati Sharma and a US-based colleague have pioneered an approach that will help designers create more efficient transport in the future.
Turbulence - the chaotic movement of fluids seen in everything from stream water to swirling smoke - has been described as one of the last unsolved problems of classical physics.
Devising a solution would reap huge benefits as reducing the turbulence-induced drag on a plane's wing by 30% could save billions of pounds in fuel costs worldwide and associated emissions every year.
The new method developed by Dr Sharma, a senior lecturer in aerodynamics and flight mechanics, and Professor Beverley McKeon from the California Institute of Technology (Caltech), makes it simpler and cheaper for scientists to study the effects of wall turbulence - when a gas or liquid flows past solid surfaces at a reasonable rate.
Dr Sharma said: "Although the equations that govern fluid flow were discovered in the early 1800s, nobody had figured out a way to predict recurring structure in wall turbulence directly from these equations."
He added: "The new work describes how wall turbulence can be broken down into constituent blocks that can be simply pieced together, Lego-like, to approach and eventually get back to the full equations."
When a few blocks, or sub-equations, are added together the results look like a full laboratory experiment but the calculations can be made on a laptop instead of a supercomputer.
Engineers now have a template to visually and mathematically identify order from the swirling flows, and will be able to use the information to improve on previous models of how turbulence works.
Leonardo da Vinci, the Renaissance painter and scientist, was also interested in turbulence and drew pictures of the eddies and currents formed when a block was placed in water.
Prof McKeon, professor of aeronautics at Caltech's Graduate Aerospace Laboratories, described the ultimate application of their research which has been published online in the Journal of Fluid Mechanics.
She said: "Imagine being able to shape not just an aircraft wing but the characteristics of the turbulence in the flow over it to optimise aircraft performance.
"It opens the doors for entirely new capabilities in vehicle performance that may reduce the consumption of even renewable or non-fossil fuels."