Detlef Lohse
“We presently live in the Golden Age of Fluid Dynamics.”
It is nearly impossible to overestimate the relevance of fluid dynamics for mankind. We ourselves are systems far from equilibrium. This implies that everything flows – panta rhei. But the same holds for the ocean, the atmosphere, industrial plants in the chemical or food industry, power stations for energy supply, transportation devices like airplanes, cars, ships, or pipelines, or, on the small scale, bacteria or microfluidic devices and processes for medical diagnostics and the pharmaceutical industry. All these systems are far from equilibrium, which implies flow, whether it be blood circulation in your body and through your heart, or the flow in the ocean or in the atmosphere that determines and affects climate. Fluid dynamics is also essential for energy production, as in combustion or in the hydrogen economy or for CO2 storage, or for additive manufacturing, which is also relevant in the health sector for printing artificial tissue or organs. These are all huge challenges for mankind, to which fluid dynamics majorly contributes and will also have to contribute in the future.
Today, fluid dynamics is multidisciplinary at its best, somewhere in between physics, geophysics, mechanical and chemical engineering, applied mathematics, and data and computer science, and ranging from the nanometre length scale to astrophysical length scales. What I particularly like about fluid dynamics is that experiments, theory, and numerical simulations go hand-in-hand, and often only by combining these methods is it possible to solve a problem.
We presently live in the golden age of fluid dynamics: The reasons are: (i) Moore's law continues to be followed for computational power, so that simulations which we did not dare to dream of even ten years ago are now possible, and (ii) a similar revolution (for the same reason) in digital high-speed imaging, thanks to which we can now routinely resolve the millisecond time scale and even smaller scales, revealing new physics on these scales, which up to now was inaccessible, and producing a huge amount of data on the flow. Moreover, other advanced equipment like confocal microscopy, digital holographic microscopy and atomic force microscopy are coming to be used more and more in fluid dynamics. Considering all of these advances together, the gap between what can be measured and what can be simulated ab initio is narrowing more quickly than we had anticipated at the end of the last century.
Other gaps are also closing. Fluid dynamics is bridging out into various neighbouring disciplines, such as chemistry, and in particular colloidal science, catalysis, electrolysis, medicine, biology, computational and data science, among many others. Here the techniques, approaches and traditions from fluid dynamics can offer a great deal of help to solve outstanding problems. Vice versa, these fields can offer wonderful questions to fluid dynamics. Academic fluid dynamics is also bridging out not only into traditional applications on large scales, such as in chemical engineering, in the food industry, or in geophysics, but also into various new high-tech applications, whether they be in inkjet printing, immersion and XUV lithography, chemical diagnostics, and lab-on-a-chip microfluidics.
For further information: d.lohse@utwente.nl
Detlef Lohse
Professor fluid mechanics, University Twente