Inspiration can come from anywhere – just watching the fascinating metal birds in the sky, witnessing the raw power of Supersonic Jets in Airshows and experiencing the awe-inspiring wind tunnel, leading to a career in Aerospace !
Swathi Krishna, our next pathbreaker, PostDoctoral Fellow at the University of Rostock, Germany, works in the field of Experimental Aerodynamics, inspired by the flight of some of the smallest species of insects.
Swathi talks to Shyam Krishnamurthy from The Interview Portal about her Bachelors thesis on building and flying a Micro Air Vehicle which bolstered her interest in applied Fluid Mechanics.
For students, when biology meets robotics meets aerodynamics, you are basically pushing the limits of physics and engineering by observing and replicating nature.
Swathi, tell us about your background?
I grew up in Bengaluru in a very ordinary, middle-class, orthodox family. My father is a (retd.) civil engineer, and my mother, a home-maker. My father had a transferable job. He sacrificed a life of comfort by not uprooting his family often, to give me a stable childhood and a solid education. This move proved to be a strong foundation for everything else that I did over the years.
My school years were filled with many extra-curricular activities. I finished my junior level in carnatic music, Bharatnatyam, played Basketball, took part in theater, scouts and guides club, and also managed to obtain my ‘Praveen’ in Hindi. The last one was my mother’s effort to equip me to get a central government job! I also remember being a major disappointment to my teachers at arts and craft!
What really interested me were aeroplanes and the night sky! It started in the 4th grade when my father took me to see the airshow. The flying metal birds, the rockets that just disappeared into the sky fascinated me and still continue to do so even to this day!
I was almost never the topper of the class but regularly moved across the scale of 2-10 in a class of 70. I think I was a curiosity-driven kid. I remember telling the class in 3rd grade that I wanted to be a scientist when the teacher asked what we wanted to be when we grew up. That desire only solidified after high school, when I attended several workshops, summer schools, and interacted with imminent scientists from the Indian Institute of Science (IISc), Indian Institute of Astrophysics (IIA), and National Aerospace Laboratories (NAL) to name a few.
I wasn’t one of those kids who tore open everything in sight to see what’s inside. One of the side-effects of being an extremely obedient kid, I suppose! As most young girls in India, I too was taught to be demure, to learn household chores, to not break things, to not talk loudly, to not ask too many questions. I was primarily being prepped for a family life. However, things changed over the years as curiosity got the better of my training and I unlearned many things. Now, figuring how things work is at the core of my job-description and I enjoy it immensely!
What did you do for graduation/post graduation?
Although I was very interested in aerospace engineering, my first choice was to study physics. I was confused but at some point I was so sure of studying basic sciences, that I did not opt for any specialised coaching for the engineering entrance exams. However, I eventually ended up giving the Common Entrance Test (CET) in Karnataka purely out of curiosity. As expected, my rank wasn’t great but it wasn’t too shabby either, considering the utter lack of preparation (I forget the number- somewhere between 2k-5k.)
Like most families in India, my family members, near and far, persuaded me to choose engineering when the CET counselling began. “Get an engineering degree and then do whatever you want.” was the most popular advice given to me. It wasn’t my first choice, but I wasn’t dreading it either. Eventually, I took up mechanical engineering for my bachelors because it resonated with me the most.
By the end of my bachelors, I was eager to travel the world and get some international exposure. I got selected for a masters in aerospace engineering at TU Delft, Netherlands, specialising in aerodynamics. I got two industry jobs after my masters but I was drawn to research. So I continued to carry out my doctoral work on the experimental investigation of insect aerodynamics which finds applications in micro air vehicles. I got my PhD from École polytechnique fédérale de Lausanne, Switzerland in 2017. Most of the projects that I did since I started masters would broadly come under Engineering physics.
What made you choose such an offbeat, unconventional and unusual career?
I never had any single role model that I wanted to emulate. Somehow nobody’s path seemed to apply to my own circumstances back then. I just took inspiration from several people from different fields to find my own way, doing things I enjoyed. Reading about the lives of great scientists and interacting with a few influenced me to a great extent. It was their striking qualities that I took note of rather than their career paths itself. In that sense, the biggest influencer was (and is) my mother. She taught me to dream big, to set goals, to work hard, to ignore the noise, and to never give up. I think those qualities are essential if you want to set out on your own path and not follow the herd.
My professor in college was a scientist from NAL. He arranged several visits with scientists and laboratories that got me a whole lot more interested in experimental aerodynamics, eventually pushing me into this field. It was through his suggestion that I did my bachelor thesis at IISc, that was a huge boost to my confidence and my CV.
There are also several other friends, colleagues, and strangers who took time to explain what they did and how, much like The Interview Portal itself! That influenced my thinking to a great extent.
A senior from college once showed me around the wind tunnel at the Indian institute of Science. As dramatic as this may sound, just walking the length of the wind tunnel was sort of an epiphany. And I dug my heels a lot deeper in experimental fluid/aerodynamics.
Biggest turning point was getting that scholarship from TU Delft to pursue my masters. I couldn’t have accepted the offer without it at the time. That place opened up my mind to a great extent. Working with some brilliant people in a state-of-the-art environment changed my thought process for the better and opened up several opportunities.
How did you plan the steps to get into the career you wanted? Or how did you make a transition to a new career? Tell us about your career path
My basic approach was to ask for advice from a lot of people in the field, writing to people already studying or working in aerospace, in India and abroad. I made several friends online who were like-minded and we exchanged notes regularly. I tried to collaborate with college seniors and other contacts. I guess, to put it simply, networking and learning more about the field in any way possible.
I tried out a bunch of topics and activities during my bachelors. For example, SAE Baja teams, robotics workshops, internships at NAL, IISc, collaborating with seniors to build micro air vehicles, organising and taking part in a few music festivals, trying to get back to basketball… I wasn’t super focussed on just one aspect during this time but aerospace was in the back of my head always. I guess every academic move I made then was somehow geared towards getting closer to aerospace applications.
I carried out my bachelors thesis at IISc alongside another colleague. We designed, developed, and flew a micro air vehicle in about 6-7 months. It involved coming up with our own design, testing materials, motors, and propellers using our own custom made rig, building the model and several failed test flights! Coincidentally, our final model flew to satisfaction on the day of the send-off event for the soon-to-be graduates!
During my third year of bachelors, one of the scientists at NAL advised me to apply to Delft. I started preparing my applications at the beginning of my 4th year along with the necessary entrance exams. Half-way during my bachelor thesis, I received an acceptance letter from Delft.
At Delft, I took part in several student projects, launched small rockets, became a freelance journalist for the university magazine, co-founded a society for international students and became its chief secretary.. I also did an internship at a small but exciting company in the Netherlands that worked on particle velocity based acoustic sensors. The years spent there were brutally tough but very rewarding!
At the company, I worked on detecting and localising acoustic sources from an unmanned aerial vehicle using a novel particle velocity sensor. For my master thesis at Delft, I worked on the aeroacoustics of impinging jets. I built an experimental setup in an anechoic chamber, and used pressure sensors, optical measurements, and microphones to investigate the characteristics of a jet impinging on a hard surface. These topics are motivated by the need to reduce noise emissions from aircraft, which is a big problem all over the world. It involves finding the major sources of noise in these cases, which originate from the fluid itself as well as fluid-structure interaction.
My time at Delft, especially in the lab during my thesis, further solidified my interest in research. I did apply for industry jobs and got a couple of them but I had a strong urge to continue in research. So I decided to do a PhD. My PhD topic was on bio-inspired flight. I investigated the unsteady aerodynamics of a hovering wing. This involved building a robotic set-up that could mimic insect flight, and using it to investigate how the flow behaves around it under specific conditions.
During my PhD, I got a very unique opportunity to work on my thesis at multiple locations through collaborative efforts. I helped build a lab from start at Leibniz university in Hannover, Germany. I built a robotic flapper and carried out the experiments there. Soon after, I got a scholarship from EPFL to go to Syracuse university in the US for a year, to join one of the leading teams in the world who specialise in advanced flow diagnostic tools. There, I applied different techniques to get relevant information from my measured data. I got back to EPFL to further analyse, write up my findings and to defend my thesis. These experiences exposed me to the scientific community around the world and was a great experience.
I was also involved with a startup right after my PhD in India, which focussed on computational mechanics. It was an enriching experience, which gave me a much needed insight into industry and its workings. However, I missed the (relatively higher levels of) freedom in academia, so I decided to get back to research. Currently, I am working as a postdoctoral fellow.
How did you get your first break?
I don’t know if there was any one ‘break’. It was (and is) about just taking every opportunity in stride and leveraging what I could. Some trials worked, some don’t. But that is the way it goes.
What were the challenges you faced? How did you address them?
Although my parents wanted me to be well-educated and supported me, their dreams for me stopped at engineering and me securing a good job at any MNC. It is a typical issue that Indian girls face (more so than guys). A job after engineering, if at all, is the first step to a “settled life”. There is nothing wrong with that for those who want it. But it is not the top priority for everyone. Convincing the family that, that lifestyle wasn’t for me was (and sometimes continues to be) a very big challenge. My choices are scrutinised more than usual and I am held answerable by many for not following the degree-job-family-life norm in India. Luckily, my folks are not too stubborn with their ideas for my life compared to their peers. They hear me out with an open mind, and give me a choice and a chance to prove myself! I take what I get and I have become better at expressing what I want over the years.
Once I somehow managed to start pursuing my goals, I realised the massive difference in the engineering curriculum in India and abroad. The teaching methods, the syllabus, the examinations in Delft were extremely different from what I was used to in India. It was a rough wake up call and it took me a while to get used to it. Especially, since Delft is one of the top universities in the world, the course load and the expectations were very high compared to the average Indian system. It was a common challenge for many Indians along with me, especially those who did not come from one of the IITs/ NITs or equivalent. One of the reasons why I think the engineering curriculum and teaching standards needs to be regularised in India. I had to shift my thinking, my approach to the subjects completely to overcome this challenge. It was a difficult period, but in retrospect, that was the best thing that could have happened. It completely changed my way of thinking for the better.
Being a female in a male-dominated field has its own challenges. From being stereotyped to outrightly dismissed to passively underestimated or overlooked, there is a bias against women. I have been asked time and again why I took up mechanical engineering as a female. Why not?! People equate mechanical engineering to physically strenuous work. Mechanical engineering is not only about being on the shop floor working on heavy machinery. Even if it were, that is no reason for women to not pursue it!
Just to give one example out of the many, when I was working for the startup in India, we visited engineering colleges to give a workshop on engineering mechanics. I was asked to meet with the principal of the college, who kept me waiting for over an hour while he was audibly chatting with his colleagues about last night’s game on TV. When he finally graced me with his time, his first question without as much of an introduction was- “So, you have a marketing background?” When I replied I had a PhD in engineering sciences, he was taken aback. His next question was -”What does your father do?” When the answer to that did not satisfy him, he went on to quiz me if I had any relatives who were in positions of power. It seemed like he was looking for an explanation as to how I could get a PhD without a legacy. I had to work hard to convince him and be taken seriously, despite a job well done at their institute. That was a blatant bias there. I’m yet to hear a man share such a story.
All my female friends and colleagues have faced bias similarly. Equipment vendors insist on talking to males even though the female is in-charge, subconscious bias against selection of women into higher roles because they tend to take maternal leaves etc., assertive women being called bossy and shrill, ideas from women being sidelined or worse stolen, assuming the primary desire of all women is to make a family, women being held to a higher standard with lesser rewards, fashion-conscious women automatically regarded as less intelligent and shallow.. The list goes on.
Unfortunately, I (and women in general) haven’t overcome this challenge yet. It is a work in progress. All I can advise other young girls and women is to assert yourself, and don’t allow this bias to induce self-doubt. Have faith in yourself and don’t lose focus of your goal. If you know what you are talking about, then get out there all guns blazing, stand up for yourself, and claim your spot. Period.
Where do you work now? Tell us about your research
I currently work as a postdoctoral fellow at the University of Rostock, Germany. I work in an interdisciplinary setting where biology meets robotics meets aerodynamics meets data processing!
My research interests are primarily in the field of experimental aerodynamics. Particularly, I am interested in understanding flow phenomena by characterising relevant flow features, their dynamics and evolution in biologically-inspired fluid problems such as insect flight, which finds applications in the design and development of flapping-wing micro air vehicles. Currently, I work on bristled wings, which is inspired from some of the smallest species of insects like thrips. They do not fly with solid wings but with wings that look like a double sided comb! Does the power consumption reduce for such wings, and if so, can we replicate it in engineering models in future? These are a few of the questions I am trying to answer now.
What skills are needed for what you do? How did you acquire the skills?
There are several skills needed for a project like mine. I use design software to create models and 3D print some parts of the experimental set-up. A major chunk of my work is getting a robotic model to work and that involves several aspects of mechanical, electrical, and control engineering along with programming. Estimating loads, calculating power requirements, choosing the right driving mechanism, building strong kinematic links that can deliver exactly what is expected of it, developing circuitry, and programming the controllers effectively come under this category. I have to design my parameter space that I wish to investigate and then carry out sensor-based and optical measurements on the robotic set-up in a fluid. That requires the knowledge of lasers, LEDs, creating and aligning light sheets, capturing sharp images which demands the knowledge of cameras, lenses, prisms, and concepts from photography like aperture, shutter speed, filters, triggering etc.. Once the raw data is acquired, image and signal processing techniques are employed to make sense of the data. That requires the knowledge of Matlab and its toolboxes or equivalent. I use some established flow diagnostic tools to analyse the data. Here, a background in aerodynamics is required too. Finally, once the analysis is done, the results need to be published and presented in conferences. So a fair amount of writing and presentation skills are required in order to convey scientific results without ambiguity.
It is hard to anticipate all the skills needed at once. The biggest skill you can have is to learn and adapt quickly when needed. Since this is inter-disciplinary and is at the edge of human knowledge, there will always be new problems and challenges. You have to be independent, proactive, and not hesitate to get your hands dirty to find solutions to the problems. These are skills that you develop by doing it. The more you do, the better you get at it!
What is a typical day like?
There are typical chunks of times in research. During experiments, I usually spend days, sometimes weeks in the lab and barely see the light of the day (especially in winters!). From soldering broken cables to calibrating expensive equipment and double checking the data collected, it involves some laborious work.
If I am processing data, I am in front of the computer, tweaking codes, producing legible graphs and drawings of the experiment.
If I am analysing, it would involve more coding, to try and connect the concepts that are already established to the new results I have found through the experiments.
If I am writing up a paper, then I’d spend weeks penning down the experiment and the findings in great detail and scientific rigor.
What is it you love about this job?
That everyday is different. There are new challenges and new problems to solve. There is a certain degree of freedom to ask the questions I like and try to answer them. It is not a process-oriented, repetitive work, which could normally get boring after a while.
How does your work benefit society?
My work on aeroacoustics of jets could find potential use in understanding and reducing noise emissions which is a major issue.
My PhD work on the unsteady aerodynamics of hovering wings could help those designing flapping wing micro air vehicles. My thesis discusses the effect of different kinematics on the aerodynamic behaviour of the wing in great detail that can find applications in design of control surfaces and flow control.
In general, a knowledge of unsteady flows can also be applied in various areas such as blood flow in arteries, heart valves, wind turbines, helicopters, atmospheric studies and so many more. Unsteady flows are everywhere!
Tell us an example of a specific memorable work you did that is very close to you!
During my PhD, I was able to produce high quality experimental data for a hovering insect-like wing that mimicked a hoverfly’s wing kinematics. I was able to demonstrate the usefulness of Lagrangian finite-time Lyapunov exponent in analysing highly unsteady experimental data. The topological analysis further helped in distinguishing the flow evolution in great detail for varying wing rotations similar to that observed in nature.
Also, spending hours inside an anechoic chamber during my masters was fun!
Your advice to students based on your experience?
Technical advice if you want to get into research-
Be curious, ask questions: no question is stupid if it means that you learn something.
Mere theoretical knowledge is insufficient. Learn to apply them to real problems. Those problems need not be on an industrial scale always. It could be something in your immediate surroundings.
Make use of websites like Coursera, edX, Youtube and so on. These websites are a huge luxury that my generation did not have while growing up. It is like being able to sit in any class you want.
Get an Arduino kit! Build small gadgets that could help you around your daily activities. There are plenty of tutorials and forums to help you with that.
It has become common to go after certificates in India. Stop doing that! Go after knowledge. No one will care about your certificates if you can’t tell what you know and how you can apply to different scenarios.
Don’t shy away from coding. I know many people (including me) who did that at some point. That would be a mistake. But also don’t assume that there is no future in the classical fields like mechanical or electrical engineering. (I was told that repeatedly when I chose mechanical engineering!). Combining the old and the new can be very stimulating.
Fluid dynamics doesn’t mean CFD only! The industry scenario in India might lead you to believe that. Experiments are and will be needed for investigation and validation. Do consider it, especially girls. You might, after all, enjoy building things, and seeing physics in action, right in front of you!
Take time to explore different fields that interest you. Especially if you do not have other responsibilities and obligations. Try to get internships even if it is right after your high school. Visit labs, industries, shop floors, cleanrooms, summer schools, museums. Engaging with people from different fields can broaden your thinking.
Don’t take up something just because most of your classmates did. Don’t shy away because of stereotypes. “Oh, mechanical is for boys”, “civil would involve standing for hours out in the sun”, “the only field that has scope is computer science”… and so many more.
Read non-academic books! It will help you imagine different worlds, learn a lot from the characters in those books, and come across a multitude of possibilities that were waiting for you to explore.
Surround yourself with people with similar interests.. It goes a long way in shaping your thought process.
Don’t hesitate to unlearn things that you have been taught. It is as important as learning itself.
Learn to take calculated risks without being impulsive. It might be scary to try and do something that you are unsure how it would turn out, but learn to work alongside the fear. More often than not, it turns out to be rewarding!
Don’t hesitate to carve out your own path. What worked for one may not necessarily work out for all and that shouldn’t be a cause of dejection. Also, everyone’s timeline is different. Just assess what you have, and use it to get where you want to go; one step at a time.
I’d also say bottle up some determination, fortitude, perseverance, and patience and run while the wind is at your back! Don’t let your own fears or of those others around you stop you from pursuing a research career.
I would like to continue to be in research and explore a wide range of topics. I would also like to get into science communication a lot more. I hope to eventually have a research group of my own, solve interesting problems, and have fun while doing it!