Background information of the project:
The bubble generation project is one that is done in collaboration with Hyflux to do aeration diffuser design study for the Membrane Bioreactor (MBR) water filtration system. The aeration of the MBR is to make use of rising bubbles to shake the filtering membranes in order to remove dirt particles on the filters to maintain efficiency of the filtration system. It is funded by MOE with a budget of $50,000 on the experimental set up which includes an air support system, a water tank and specimens in the water tank, which currently include aeration pipes and a bubble generation plate, with the high-speed camera alone costing $50,000. For the Final Year Project (FYP in short) that was to be done by a final year student, which is also one of our mentors, he got $600 for the purchasing of the chemicals needed. Currently, the set up only takes up a corner of the hydraulics lab at SIT with 2 professors, 2 researchers as well as 3 students using it. At the point I joined the project, it is already in “stage 2” where preliminary research has already been completed last year and it is now given to final year students as their FYPs to conduct experiments according to their own plan and to collect additional data for the bigger research task.
Picture 1:The area of the experimental set-up in the lab.
Picture 2: The set-up itself.
Picture 3a and 3b: Photos with our two main mentors, Joo Guan (on left) and Shuek (on right).
Elaboration on the project and its purpose:
This project is created to find the optimal bubble size as well as the frequency to be used to clean dirt and other impurities that got caught by the filter fibres after the water is cleaned by the filter. When this project can be successfully completed, it will bring about many benefits, such as increased efficiency of the filtration system, reduced power consumption and therefore reduced operation costs as well as being indirectly more environmentally friendly. The steps to complete the project includes testing the viscosity of different mixtures of glycerin as well as water in small samples, increasing the glycerin-water mixture to a suitable height when conducting the experiment and finally turning on the air flow, recording the bubble flow using the high-speed camera and finally analyzing it using the analysis app.
Elaboration on tasks that we participated in:
Despite not having a final product or result to work to, we did not just sit around and do nothing and instead we participated in a few different experiments to learn about the project as well as knowledge that is related to the project. Firstly, Joo Guan, our first mentor, gave us the tasks to read 2 different papers as an introduction, then we tested for the specific flow rate which slugging will stop in the case of a pipe with 5 holes of 5mm in diameter each. The specific flow is one that will cause slugging to stop when the set flow rate is higher than this value and slugging will occur when the set flow rate is lower than this value. Slugging is a phenomena where the waves of the water in the pipe becomes high enough to reach the top of the pipe, thus causing the air flow to not be continuous. Not only so, we also measured and calculated the critical height of the liquid in the pipe which would cause slugging to occur as well as having to find out why the calculated and measured values are different. After this introductory experiment and reading was done, we went on to attach to the main project that aims to find the optimal flow rates for holes of different diameters in different viscosity of the liquid used. This project is being done by Shuek, our second mentor. This experiment started with using a digital viscometer to measure the viscosity of samples of different ratios of glycerin and water which was done by Shuek and a friend while we observed them. After that, it was just testing different flow rates with a fixed hole diameter and recording and analysing the captured footage of the bubbles using a high-speed camera. This was all done in just water and can be considered as the collection of data for the "mixture" that is 100% water. After that, some planning was done to devise a plan to do the main experiment with accuracy and speed. With a limited budget given to the FYP, there was only enough money to get enough chemicals to do the actual experiment once and only once, therefore with a tense heart we started the experiment. As per what we have planned before, we started with 100% glycerin (as shown in the pictures above) and added water afterwards, to lower the concentration of glycerin and hence the viscosity. After obtaining the first data set with 100% glycerin, the diameter (of the widest point) of the bubble was measured and the bubble modeled and verified using SolidWorks, a 3D modelling application. When the first set of data was verified to be accurate (and thus the experiment was proven correct), all the data sets collected afterwards were just saved as videos due to limited time and many sets of data that are needed to be collected.
Picture 4: Adding glycerin into the water tank.
Picture 5: Adding in containers of water to make the glycerin reach a desired height.
Picture 6: Analysis of bubbles.
3 content knowledge/skills I learnt:
2 interesting aspects of my learning:
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.