School research reveals secrets of nanobubbles
Supercomputer simulations
Researchers from the School’s Institute for Multiscale Thermofluids, the late Regius Professor of Engineering Jason Reese, Dr Matthew Borg, and postgraduate research Duncan Dockar, modelled complex simulations of air bubbles in water, using the UK’s national supercomputer.
These simulations revealed details of the growth of so-called nanobubbles, which are tens of thousands of times smaller than a pin head.
The team modelled the motion of atoms in the bubbles and observed how they grew in response to small drops in water pressure. They were able to determine the critical pressure needed for bubble growth to become unstable, and found that this was much lower than suggested by theory.
This rapid expansion and collapse of bubbles, known as cavitation, is a common problem in engineering but is not well understood.
Potential applications
The findings could lend valuable insight into damage caused on industrial structures, such as pump components, when these bubbles burst to release tiny but powerful jets of liquid.
The discovery could also inform the development of nanotechnologies to harness the power of thousands of jets from collapsing nanobubbles, such as therapies to target some cancers, or for cleaning high-precision technical equipment.
Researchers have proposed an updated theory on the stability of surface nanobubbles, based on their findings.
Duncan Dockar commented: “Bubbles routinely form and burst on surfaces that move through fluids and the resulting wear can cause drag and critical damage. We hope our insights, made possible with complex computing, can help limit the impact on machine performance and enable future technologies.”
Their study, published in Langmuir, was supported by the Engineering and Physical Sciences Research Council.
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