Chemo-hydrodynamics at radial reaction fronts
Contact person: Dr.-Ing. Karin Schwarzenberger
Project staff: Dipl.-Ing. Yorgos Stergiou
Funding: German Aerospace Center (DLR) with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag (Grant No. 50WM2061, project ChemFront)
Motivation
Reaction-Diffusion-Advection (RDA) fronts are phenomena present in a wide variety of disciplines; ranging from disease spreading to nanotechnology and from image processing to CO2 sequestration. In spite of this, the complete mechanism and dynamics of such systems is yet to be understood. In order to achieve this the buoyant effects in such systems experiments are conducted in the microscale and various experimental micro-gravity platforms are utilized.
A typical reaction front under normal gravity
Schematic of the reaction front under investigation
Goals
- Investigation of flow patterns and instabilities in reaction-diffusion-advection fronts
- Compare results with existing theory and propose new models
- Transfer knowledge to industrial applications (soil reparation, art restoration, re-calcification)
Methods
- Experiments in custom-made experimental microscale devices (such as Hele-Shaw cells and ultra-thin capillaries)
- Flow visualization techniques (i.e. μ-PIV, stereo-PIV)
- Utilization of micro-gravity platforms (TEXUS 57 sounding rocket mission, 73rd ESA parabolic flight)
Results
An optimized experimental device (radial Hele-Shaw cell) was used for the investigation of such RDA fronts with the aim to optimize initial conditions and minimize entrance effects.
Initial results from experiments in parabolic flight are suggesting a strong dependence of RDA front dynamics on buoyant effects.
A buoyant, density-driven instability is also observed in such systems and is furtherly investigated.
Publications
Y. Stergiou, K. Eckert, K. Schwarzenberger, Entrance effects in a radial Hele-Shaw cell: Numerical and experimental study, Chemical Engineering Journal 428 (2022) 131146
Y. Stergiou, M.J. Hauser, A. Comolli, F. Brau, A. De Wit, G. Schuszter, P. Papp, D. Horváth, C. Roux, V. Pimienta, K. Eckert, K. Schwarzenberger: Effects of gravity modulation on the dynamics of a radial A+ B→ C reaction front. Chemical Engineering Science 257 (2022) 117703