When liquid such as water flow fast enough, it will experience turbulence- random changes in velocity and pressure within the fluid. It is challenging to study turbulence. However, understanding turbulence is essential to design efficient turbine blades.
Current engineering models of turbulence depend upon empirical relationships. These relationships based on previous observations and do not based upon underlying physics. It is because; underlying physics is very complicated and could not solve even simple problems.
To solve long-lasting question in turbulence, researchers at Imperial College of London used supercomputers, running simulations on graphic processors.
Co-author Dr. Peter Vincent, from the Department of Aeronautics at Imperial, said: “We now have a solution for an important fundamental flow problem. This means we can check empirical models of turbulence against the ‘correct’ answer, to see how well they are describing what happens, or if they need adjusting.”
The team tried to answer a simple question, if a turbulent fluid is flowing in a channel and it is disturbed, how does that disturbance dissipate in the fluid?
To determine the overall behavior of the fluid, the team had to simulate the myriad smaller responses within the fluid. They run thousands of turbulent flow simulations, each requiring billions of calculation on supercomputers. These simulations helped them to determine how the disturbance dissipates in the flow and requirements that empirical models must satisfy.
Co-author Professor Sergei Chernyshenko, from the Department of Aeronautics at Imperial, said: “From my first days studying fluid mechanics I had some fundamental questions that I wanted to know the answers to. This was one of them, and now after 40 years, I have the answer.”