Innovative In-Situ experimental Techniques

We develop innovative optical technologies to investigate the thermal and fluid dynamics of bubble behaviour, enhancing the precision of electrochemical research and mass transfer phenomena in multiphase flow systems.

Motivation

Accurate measurement of space- and time- resoved thermal gradients, disolved gas concentration field and fluid motion around bubbles is essential for understanding and optimizing electrolyzers. Traditional methods lack the resolution to capture these subtle but critical effects.

Goals

• Adapt Schlieren imaging for high-resolution, in-situ studies of gas bubbles.
• Correlate temperature fields with bubble dynamics.
• Validate theoretical models of Marangoni convection and thermal gradients.
• Establishing correlations between concentration fields and dynamic behavior of bubbles.

Techniques

Schlieren imaging system; PIV; PTV; Planar Laser-Induced Fluorescence (PLIF) 

Results

Dimensionless Schlieren images and refractive index field for hydrogen and oxygen bubbles

Quantified oxygen bubble mass transfer on uncoated and coated Ti64 substrate by combined PLIF and shadowgraphy

Publications:

1. A. Bashkatov, A. Babich, SS Hossain, X. Yang, G. Mutschke, K. Eckert, H₂ bubble motion reversals during water electrolysis, Journal of Fluid Mechanics, T. 958. – C. A43. 2024

2. A. Babich, A. Bashkatov, X. Yang, G. Mutschke, K. Eckert, In-situ measurements of temperature field and Marangoni convection at hydrogen bubbles using schlieren and PTV techniques, International Journal of Heat and MassTransfer, T. 215. – C. 124466. 20243.

3. Dai, H., Yang, X., Schwarzenberger, K., Heinrich, J., & Eckert, K.,Wettability-dependent dissolution dynamics of oxygen bubbles on Ti64 substrates, Journal of Heat and Mass Transfer, 2025, 236, 126240