Flow simulation wins Visualization Competition 2017

"A clear example of the power of computing and visualization"

19 DEC 2017

Alexander Blass of the University of Twente has won the Visualization Competition 2017 with a visualization of direct numerical simulations of sheared thermal convection. The prize was awarded at the Super D Event on December 12.

The winning entry, Direct numerical simulations of sheared thermal convection, was created by Alexander Blass (MSc) from the Physics of Fluids Group, University of Twente. He received a prize of € 500 in gift certificates. The jury comments: "A great visualization of a large scale flow simulation, nicely showing the emerging patterns. A clear example of the power of computing and visualization, while also being very beautiful and intriguing."

Large-scale meandering structures

Shear-driven flow can be either imposed by a pressure gradient or through the implementation of moving walls. A simple way to realize this is plane Couette flow, where the top and bottom wall move in opposite directions to shear the flow while keeping the mean flow velocity neutral. The shearing motion increases the momentum exchange and cause large scale structures to emerge, which fill the whole channel. Solely buoyancy-driven convection, such as Rayleigh-Bénard flow, is used as unstable flow stratification to enforce thermal convection from a lower, heated plate to a higher, cooled plate. This can be the numerical origin for phenomena such as ocean dynamics, clouds and atmospheric physics in general. The main drive for the heat exchange are large scale structures which are initiated by the motion of thermal plumes.

Combination

While these two phenomena separately are very well studied and understood, their combination is far less researched. The visualization reveals the final outcome of clear large scale meandering structures which are significantly more prominent than the large structures already observed in plane Couette flow. Depending on the choice of control parameters, these structures can be varied in thickness, number and wavelength. This type of flow, where buoyancy and shear interact, is a vital process in the area of fluid dynamics and the foundation for many mechanisms in nature. The visualization is vital for the understanding of the development of the large-scale meandering structures that emerge due to the interaction of thermal convection and sheared forcing. 

About the competition

In the SURFsara Visualization Competition users of the Dutch National e-Infrastructure can enter visualizations of their research, thereby communicating their work and results in an attractive manner. The competition entries were judged by a panel of Dutch visualization experts from academia, plus representatives from SURFsara. Entries were judged on effective communication of research and results, visual aesthetics and impact, skills required in making the visualization and use of the Dutch National e-Infrastructure.

This year the competition received 8 entries, from varying scientific fields. The top 3 results are:

  1. Direct numerical simulations of sheared thermal convection - Alexander Blass (University of Twente) 
  2. Clouds over the Netherlands - multiscale simulations for locally improving a global weather model - Fredrik Jansson et al. (CWI, Åbo Akademi University, Turku, Finland; Netherlands eScience Center)
  3. Activity wave in human primary visual cortex V1 - Matthias Ekman (Donders Institute) 

Photo Vera Duivenvoorde

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Latest modifications 21 Dec 2017