ZHU YUEAN

Picture 3a and 3b: Photos with our two main mentors, Joo Guan (on left) and Shuek (on right).

3 content knowledge/skills I learnt:

• How to use the air supply system using compressed air, why is it used as well as some of the essential procedures regarding it. Despite the presence of a main air compressor pipeline nearby, the experimental set-up did not draw compressed air directly from it but instead stored air at a needed pressure in air canisters below the set-up. This was done as pressurized air canisters at a constant pressure provided a more consistent flow or air compared to active pumps. The air flow regulators at the left side of the water tank are also separated from the pipe that leads to the water tank by a pressure chamber at a higher elevation to prevent water from going into the electronics and making them out of order. The flow rate of air into the test specimen in the water tank can be controlled by a control panel at the top left corner of the set-up with other functions that can be controlled as well such as backlights and water height regulation. The system was also surprisingly easy to use as the desired flow rate can be set and the regulators can be turned on and off using switches on the panel. Not only so, the flow rate can be controlled to the nearest 0.1 standard litres per minute (SLM) as there are regulators with different maximum flow rates such as 100 SLM, 50SLM, 10SLM and 1SLM.
• Another skill that i have learnt would be the usage of high-speed camera to record and do preliminary analysis of bubbles generated. I was also surprised at first by the fact that unlike normal cameras, the high-speed camera does not have a screen to view the captured footage and would have to be connected to a computer or laptop to even operate it. The apps that are used to view and control the camera came along with it as any other applications would not be able to do such a thing. The capturing app can also do preliminary analysis of the dimensions of the bubble as it would be able to measure lengths straight from the footage captured, however, the length has to be calibrated with a certain known length first before any measurement can be done. The known length that it is calibrated against is usually another aeration hole on the bubble generation plate for convenience and accuracy.
• Despite not being able to be involved in a simulation, in this case, Computational Fluid Dynamics (CFD), due to the lack of time, we still learnt quite a bit about how simulations are done for travelling entities which can be either solids or fluids (liquids and gases). For the simulation for moving solids, the motion for every part of the solid can be tracked individually as solids usually stay in the same shape and size throughout most, if not all of their journey. On the other hand, it would be impractical to track every individual part of a fluid due to its nature to change shape and size during its travel, costing more time and having a need for a greater amount of computing power in order to run that simulation. Due to these reasons, a different method is used for the simulation for movement of fluid, this method is called "meshing". This method works by dividing the area which the fluid will be in into small cubes where the fluid itself is not tracked but the contents and position of the contents in the small cubes are tracked (e.g. 50% water and 50% air with air above the water). After all the cubes are tracked, the movement, velocity and other parameters of the flowing fluid can be mapped out and allowing the simulation to be done easier.

2 interesting aspects of my learning:

• The first interesting aspect would be that experimental projects are not just about repeated experiments again and again with nothing else to do, instead, experiments themselves only take up a portion of the time that is spent on the project. The other portion of the time will be spend on other perhaps not so interesting but still essential for the progress of the project such as research, project planning, material acquisition and processing of the data collected.
• The second interesting aspect would be that i thought that experiments are going to have a rigid process and fixed way of doing due to the numerous rules and regulations that are in place during lab experiments. However, it turns out that there is still much room for innovation as the rules are a general guideline on what to do and what not to do in a lab.

1 takeaway for life!

I think my takeaway for life from this month long WOW! programme would be the qualities needed to successfully do a long-term research project well, these qualities will also be applicable later on during work in terms of almost any type of projects. This is because projects usually do not have very clear instructions on what to do but only provide a general overview of the field where research should be done in. Due to that reason, an important quality to have is a clear mind on what is the goal to be achieved by the end of the research project so that it would be focused on and that the research (or work) will not go off plan. Not only so, time management skills would also be vital to the success of such long-term projects due to the sparse and limited amount of progress checks there are, there is probably only monthly, if not quarterly progress reports depending on the length of the project. Due to the loose checking of progress, it would be easy to waste large amounts of time on other fun-but-not-helpful activities such as checking social media, for example. Therefore, good time management skills would allow us to keep ourselves on track and not end up with the consequences of incomplete work despite the time given. Lastly, as there is usually limited budget given to such projects, a creative mind would also be needed to find materials and other essential resources that will both work well and be friendly to the wallet. Not only will creativity be needed to make progress on projects, it would also be needed to solve problems that will crop up along the way of the project (just like how the liquid level would be insufficient to conduct the experiment, needing to use bottles of water to make it high enough which can be seen in Picture 5).

All in all, this month long WOW! programme was really beneficial and insightful for me as not only did I get to do something that I have never done before in my school life, but also learn numerous skills and knowledge that would either be difficult to obtain in a school environment or will only be taught at a much later time. Therefore, I am very grateful that the school provided me with such a rare and useful opportunity to be attached to a external organisation of my choice for one month to both learn and have a feel on what working might be like in the future.