"Interfacial instabilities driven by vibrations in microgravity" is the title of the image submitted by Pablo Salgado, PhD student in the School of Aeronautical and Space Engineering (ETSIAE) at the Universidad Politécnica de Madrid (UPM), to the Scientific Photography “Gravity Science Image Contest”.
The image has won the competition among 23 contestants of this third edition, organised by ELGRA (European Low Gravity Research Association), whose last symposium was held last September in Granada. The vote, taken by the participants attending the congress, who valued the following aspects: relevance of microgravity or hypergravity context, scientific-educational content, creativity, aesthetics and artistic value.
Taken during a parabolic flight
This snapshot captures the coexistence of different instabilities within a fluid system subjected to vibrations, and it is the result of experiments researching the response of immiscible liquid layers under microgravity conditions . Within space environments, where fluids are usually part of life support or propulsion systems, vibrations naturally arise from several sources, i.e. mechanical elements or astronaut activities during manned missions.
The origin of the photography is on a parabolic flight led by the Fluid Mechanics group of the Microgravity Research Center at the Free University of Brussels, coordinated by the researcher Valentina Shevtsova, in cooperation with the EUSOC and the Space Science and Operations research group at UPM, to which Pablo belongs.
Since liquids are crucial to many space applications, it is important to understand their response to microgravity. Therefore, comparing theory and experiments is essential to discover, understand and predict such behaviour, partly captured in this image.
 P. Salgado Sánchez, V. Yasnou, Y. Gaponenko, A. Mialdun, J. Porter and V. Shevtsova. Interfacial phenomena in immiscible liquids subjected to vibrations in microgravity. Journal of Fluid Mechanics 865, 850-883 (2019).