Effect of Wall Surface on Bubble Rise Velocity

Topic: Effect of Wall Surface on Bubble Rise Velocity

Student: Joachim Eng

Supervisor: Dr Lau Ee Von

Throughout the UROP journey, Joachim Eng, a third-year mechanical engineering student has undergone research for 3 months in semester 2/2021 and extended to the summer break for an additional 3 months.

The research aims to investigate the effect of adjacent wall surface materials with different polarities on the bubble rise velocity. The experimental set-up consists of a water column with a syringe attached at the bottom section for the injection of air bubbles where its velocity is captured by a slow-motion camera at 120fps. Ultimately, although the oscillations of a rising bubble are more prominent with a hydrophobic wall compared to a hydrophilic wall, the difference in rising velocity is insignificant, consequently, the need for further work to be conducted with a reduced bubble-to-wall distance and a larger bubble diameter for additional justification.

Figure 1. The experimental setup (left and, water tank drawing (right)

Figure 2. The rise velocity of bubbles adjacent to a non-slip wall (left), hydrophilic wall (centre), and hydrophobic wall (right)

What Joachim said about his UROP experience

“It’s an amazing opportunity and experience for me to work in the research line early on in my third year. Furthermore, this is a good head start before involving in my Final Year Project (FYP). For those who intend to do a postgraduate study, starting in UROP and then extending your research to your FYP days will possibly allow you to publish your work at the end of your undergraduate study and increase your chances of landing a scholarship.”