Alice Muthurajavel
“To be honest, I just thought airplanes were super cool!”
“When I was at school, I was determined to become an aerospace engineer. But back then it was still very vague, because, to be honest, I just thought airplanes were super cool”, explains Alice Muthurajavel. During her master’s degree, the mechanical engineering graduate eventually specialised in simulation science.
Today, at the Institute of Propulsion Technology, she is developing a spray solver for the institute’s in-house flow solver, TRACE. This enables TRACE to simulate the combustion of liquid fuels. More specifically, the researcher is examining the atomisation of liquids and the movement of their droplets.
Alice explains that there are two different methods for creating a simulation of fluids. In the first method, one looks only at the inlet and outlet of a geometry – for example, a pipe. The analysis focuses on what goes in at one end and what comes out at the other. “This is very practical for simulations where not every particle within the geometry needs to be tracked”, explains the researcher. You only need the pressure and temperature at the inlet and outlet for the calculation. “This works very well for combustion with gaseous fuels”, she says.
However, if you want to simulate liquid fuel, such as kerosene, the method reaches its limits. “Liquid fuel must first be atomised into many small droplets and vaporised before combustion can take place. To obtain a precise simulation, these small droplets must be tracked individually”, explains Alice. This is a different simulation process from the main solution method in TRACE. “Technically speaking, it’s actually easier, because you simply have to solve Newton’s equations. So, you track a particle moving at a certain speed on which a force is acting. Conceptually, it’s easier to understand, although it can of course become more complex with different methods”, she says with a laugh.
What Alice would say to young scientists: “I’m pretty sure that as children we’re very curious about certain things. And then you realise, somehow, that the world doesn’t always encourage you to explore those things. If you’re passionate about something, just go for it! STEM subjects are quite difficult for everyone, you’re not the only one – so don’t give up!”
Accuracy vs. effort
To develop the spray solver, Alice’s main task is writing software. However, literature research, debugging (troubleshooting and fixing errors), validation and model development also make up a large part of her daily work. Depending on the stage of the project, she therefore focuses on different tasks. “Sometimes it takes three days to write the code, and then another two days for testing. My day-to-day routine therefore always looks a bit different, depending on what I’m currently working on”, she explains.
The biggest challenge for her is striking a balance between accuracy and effort. “When programming, you want to achieve a certain level of accuracy, but then you realise: to achieve that level of accuracy, you spend a great deal of time on just one step. And then you ask yourself whether the accuracy gained is actually worth the time spent”, says Alice.
Finding the right balance isn’t always that easy. “I think you can only learn that with time and experience”, she admits. She is therefore looking forward to learning a lot from her colleagues in this regard.
Are you curious and keen to pursue your interests? The DLR_School_Lab regularly offers internships at the DLR in various disciplines.
