Student practical training / Master theses

Evaporation of microlayer is one of main contributions to the bubble growth. The microlayer is a micro meter scale thin liquid layer underneath a nucleated bubble over heated surface. Heat transfer surface characteristics play a crucial role in the formation and the vaporization of this layer. The effects of surface characteristics, especially the roughness effects on the microlayer thickness did not receive that much research interest. The present study aims to predict the surface roughness effects on the initial microlayer thickness during the microlayer formation and it’s contribution to the bubble growth. An experiment will be performed in a borosilicate glass vessel. Bubbles will generate from artificial cavity on a laser treated stainless steel surface. The laser treated surfaces will influence the microlayer formation and bubble growth. An empirical expression will be developed to capture the initial microlayer thickness as a function of surface roughness profile (height in this work).

Investigation process: experimental and numerical

• Capturing nucleated bubble of degassed deionized water using high-speed imaging techiques for different heaters
• Processing the captured results using image processing tools
• Consideration of uncertainities related to experiment and data processing
• Analyzing experimental data setup
• Numerical calculation of associated heat transfers using MATLAB
• Development of an empirical correlation based on experimental data.

• Academic studies in the field of process engineering, chemical engineering, mechanical engineering or comparable fields of study.
• Knowledge in heat and mass transfer phenomena
• Expertise in MATLAB or similar coding

• Literature research – nucleate bubble dynamics
• Experiment using imaging techniques
• Processing the experimental results
• Analyzing the results