V0036: Chemical Flowers: buoyancy-driven instabilities under modulated gravity


V0036: Chemical Flowers: buoyancy-driven instabilities under modulated gravity

Stergiou, Y.; Horvath, D.; Schuszter, G.; Hauser, M.; de Wit, A.; Eckert, K.; Schwarzenberger, K.

In this video, we present experiments of a miscible reactive horizontal displacement in a radial Hele-Shaw cell under modulating gravity levels.Initially, the Hele-Shaw cells are filled with a colorless solution of KSCN, and the injected fluid is a colorless solution of FeNO3. When the two solutions react, a complex ion (FeSCN2+) forms resulting in a red-colored product solution. Due to the direct visualization of the formed product using a white LED light array and a monochrome camera, this chemical system is convenient to study reaction-diffusion-convection fronts [1]. The gravity modulations were achieved aboard the 73rd ESA Parabolic Flight Campaign that took place in October, 2020 in Paderborn, Germany. The parabolic flight allowed for experiments under micro-g, normal-g and hyper-g conditions and the transition between them. These experiments provided detailed insights in a previously investigated [2] buoyancy-driven instability. In particular, the effect of hyper-g and multiaxial acceleration on the pattern formation was revealed. The observation of the system under micro-g confirmed that no instability develops in the absence of buoyancy effects.

[1] A. Tóth, G. Schuszter, N.P. Das, E. Lantos, D. Horváth, A. De Wit, F. Brau, Effects of radial injection and solution thickness on the dynamics of confined A+ B→ C chemical fronts. Phys Chem Chem Phys, 22(18), 2020

[2] F. Haudin, L. A. Riolfo, B. Knaepen, G. M. Homsy, A. De Wit. Experimental study of a buoyancy-driven instability of a miscible horizontal displacement in a Hele-Shaw cell. Phys. Fluids, 26(4), 2014

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Publ.-Id: 34641