Back Story: Ashley van Bruygom, “I don’t mind that I fit the stereotype”

Shini Somara: What is your research specifically looking at?

Ashley van Bruygom: I’m based at the National Centre for Combustion and Aerothermal Technology at Loughborough University, where I’m researching hydrogen combustion for aviation. I do this under extremely controlled settings using Computational Fluid Dynamics, essentially simulating flames on the computer!

In aviation, hydrogen is a relatively new concept. There is lots of history, and knowledge when it comes to burning hydrocarbons, but hydrogen is completely different. For a start, it’s not a liquid, so we don’t have to worry about atomising it. However, as a lightweight gas, it is easy to burn and therein lies one of our greatest challenges.

Hydrogen can be stored as a gas in a highly pressurised vessel or can be cooled to extreme temperatures and stored as a liquid. Liquid hydrogen can be handled and transported more easily but burning it in this state is not so easy, especially when operating at scale.

There are many fascinating problems to solve with hydrogen and we are only at the beginning. I find hydrogen research really exciting, especially within aviation.

SS: We have recently made great progress with hydrogen in aviation; is it a viable future transport fuel?

AvB: Yes, recently we saw our first hydrogen-powered aviation ground tests and I do think hydrogen is a fantastic answer to generating power. Within aviation, hydrogen is certainly a solution for short-haul flights, however, for long-haul flights, there is still the question of storage. A huge amount of space would be needed to store the number of containers needed for a long journey. As hydrogen doesn’t seem to be the solution for long haul, sustainable aviation fuels (SAF) are being developed instead. With SAF, you are still burning carbon; however, it is often produced using waste carbon, closing the carbon loop, adding no additional carbon entering the atmosphere. This is another exciting challenge for engineers.  

SS: What are other challenges to using hydrogen in aviation?

AvB: The by-product of burning hydrogen is not only water, but also nitrogen-based emissions or NOx. NOx can be responsible for the generation of ozone in our atmosphere. This is not my area of expertise but will also be researched and addressed. As with hydrocarbon-powered jet engines, hydrogen flights will also generate contrails, which are known to trap heat in our atmosphere. Contrails are formed when water crystallises around tiny particles of soot (or tiny carbon-based particles). Exhausted water from hydrogen jet engines will also crystallise, and we can’t say at this stage what the effects of these different types of contrails will be, in terms of their contribution to climate change.

SS: In terms of hydrogen-powered travel, have we come a long way since the Hindenburg?

AvB: Absolutely! By the time we take hydrogen-powered planes, the plane itself will have gone through so many tests and phases of study that I don’t think it will be any more dangerous than flying with kerosene. Putting hydrogen on trucks and in cars may, in fact, entail more risk, just as statistically there are more accidents on the road than in the air. Going forward, more hydrogen research may be needed on the ground.

SS: Loughborough is part of a CDT. Tell me more about this collaboration?

AvB: The Centre for Doctoral Training in Future Propulsion and Power is a joint venture between Loughborough, Oxford and Cambridge Universities. Cambridge University maintains an expertise in turbomachinery, Oxford University specialises in thermofluids and Loughborough brings their expertise in combustion. Together it’s a powerful union of research skills, especially for the aviation sector. I am proud to be part of it!

SS: Any advice for the under-represented in engineering?

AvB: Maintain a strong sense of self. Many people will always try to pigeon-hole us or change the way we are, so as to conform. I’ve met some very non-conforming engineers along my education, some of which have been incredible mentors. Despite being in a minority as a woman in aeronautical engineering, I have always followed my keen interests in aviation and engineering. I don’t mind that I fit the stereotype, in fact, I quite like it! I work with colleagues who are all focused on our work output, rather than who we are as individuals. This is the most positive aspect of being part of the CDT. Everyone has a common goal of making aviation more efficient, sustainable and world leading.