Pushed by the drive for sustainability, novel propulsion systems that until relatively recently seemed years away are quickly coming into focus.

Organizers of the 25^th International Society for Air Breathing Engines (ISABE) conference discuss some of the fast-emerging technologies.

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Rush transcript:

Guy Norris:

Welcome to this week's edition of the Check 6 podcast. I'm Guy Norris Aviation Week senior editor. On the cover of last week's Aviation Week, we featured Eviation's Alice, which is the first purpose-designed all-electric commuter aircraft to enter flight test. Representing a milestone development in electric aviation, the test debut of Alice is symbolic of the breathtaking changes we're now seeing underway across aerospace propulsion in areas ranging from sustainable aviation fuels and hybrid electric powertrains, to next generation geared engines, open fans, and hydrogen combustion. All of these topics were discussed at the recent is ISABE Conference in Ottawa, Canada.

ISABE stands for the International Society for Air Breathing Engines. And that's where I had a chance to sit down with Shaji Manipurath, who is the director of research and development at the National Research Council of Canada's Gas Turbine Laboratory and the president of ISABE, Ric Parker. I began asking Ric how the increased drive for sustainability since the last ISABE conference in 2019 has accelerated these developments, many of them at the time a mere twinkle in the eye of researchers.

Ric Parker:

Before Covid, everybody was talking about this stuff but there wasn't as much happening. Now we're seeing real results from people driving down CO2. So, across the engine industry there are a number of things we can do and we heard this week what people are doing.

From all throughout the history of ISABE, the big push has been to increase the efficiency of aircraft engines, mainly to make them go faster, to fly higher and use less fuel. It wasn't in the past dominated by the environment. Now though it's come to the fore. We have to use as little fuel as possible, create as little CO2 as possible and think about mitigating some of the other non CO2 effects of air transport. But on top of that, we've seen, coming to the fore, whole areas like electric propulsion or partial electric propulsion, so-called hybrid propulsion, where we combine traditional engines with batteries with electric motors and can then make some very serious dents in the carbon footprint of travel.

And the other thing we've heard a lot about this week is alternative fuels that can be virtually no carbon or net zero carbon. So, in the case of hydrogen, no carbon, there's no hydrogen in, no carbon in the fuel. So, if you burn hydrogen and it burns very nicely and very fast and very hot, you can propel an aircraft engine with a gas turbine like today, without leaving any CO2 behind it all. Or, you can put it through a hydrogen fuel cell, create electricity and drive in electric mode. We got those two options.

And then people are talking a lot about synthetic aviation fuels. So, we've been hearing for many years about biofuels, but this new power to liquid SA, for synthetic aviation fuel, that's really about taking carbon out of the atmosphere. Carbon dioxide, capturing it from the atmosphere. Producing hydrogen, using green electricity, infusing those two back together to make a new fuel. And then yes, you burn it and you let the CO2 back out, but that cycle is net zero. You've captured it, you've taken it out the atmosphere, you let it go again. So all these things give us great hope for the future and we've heard some very, very interesting things from the main- All the main engine makers are here, Pratt & Whitney, Rolls Royce, GE and the airframers are here, Boeing, Airbus, Bombardier. So, everybody's pulling in the same direction. There's a remarkable similarity between all the talks in terms of the topics and what people are doing about it. So, I think there's a great consensus across the industry of what we need to do.

Guy Norris:

And Shaji, of course, you are hosting us here at this conference in many ways. You provided an excellent tour to the attendees yesterday to the NRC facilities. What's your take on... Because you've of course spent years, really, preparing and planning for this conference. So, you must be relieved. It's almost done in that respect.

Shaji Manipurath:

I think things have gone beautifully here. The weather notwithstanding. We've put together a first class technical program here and it's great credit, not just to myself and my organizing committee, but also the ISABE board members with their deep connections in the industry. Hearing from all the major OEMs, from airframers to engine manufacturers. And also, different perspectives. We had a keynote on equity, diversity and inclusion. We've had keynotes from think tanks. So, it's absolutely brilliant that we have put together this program here.

And the focus of the conference this week is on greener technologies for a sustainable future. So, while the theme of the conference has been angled as such, we've also had diverse topics ranging from supersonic flight to business aviation. So, I do think I would characterize this conference as a tremendous success from that perspective. It's also the first time we've actually convened after Covid and we're convening here in Canada, in Ottawa, which is the capital city of Canada. Canada has one of the most significant... It's a very significant aerospace player in the world. Also, in Canada, the aerospace industry is also the number one investor in R and D nationally with about 710 million annually being spent here. So, investing in our future, investing in the aerospace's future, sustainability, is a tremendous thing in Canada and we are really proud to host this conference right here in Ottawa.

Guy Norris:

And I think the delegates are impressed, generally, by, probably for the first time for many of them, seeing the facility that you showed nearby to the city, including the hybrid electric test bed that you've developed, the heat aircraft, which is a modified Cessna 337 with its standard piston engine up front and electric motor behind, between the two booms. Just as an example of things that we would never have seen just a few years ago, and here they are right there on the ramp. Or in this case, in the hangar.

Shaji Manipurath:

We are absolutely seeing a lot of technology demonstrators coming to fruition worldwide. It's a type of thing that I think is an indication of things to come in the near future. I think we are going to see a lot of the technology demonstrators today evolve into some form of commercially viable systems probably within the next decade or so. And just as a personal note, I know some of these projects were happening throughout the pandemic, so even as the pandemic was raging and even as people were working from home with Zoom meetings, work still had to be done and a lot of these projects actually came together in the last two to three years during this interesting period.

Guy Norris:

Right. And, actually, you raise an excellent point. The thing about ISABE, which I think is uncanny somehow, is that during the actual event... For example in 2017 in Manchester, Rolls Royce announced that they'd just run the power gear box for the ultrasound at a record setting. This week we've had the aviation Alice all electric commuter aircraft made its first flight and coincidentally the Clean Aviation European Union's joint partnership has announced the clearance for the next phase. 20 new projects, 20 new acronyms that we're all going to have to love and learn. So, it does seem to be remarkably good timing every time for the conference.

Ric Parker:

Yeah, I think we always have something new to celebrate and we had a representative here from the Clean Aviation Group in Europe. It's an industry private partnership with the European Commission. I was chairman of its precursor clean sky Two for seven years and it's achieved wonderful things. We heard mainly what it achieved in that Clean Sky Two program, pushing this whole environmental agenda forward, not just, we always think of the CO2 side, but low noise. Noise is still an issue that, the noise to the public, it may not harm anybody physically, but you don't want to live under an age of flight path. And that Clean Sky program certainly did a lot to push down noise as well as introduce some of these novel technologies.

But you're right, this week's announcement of the first tranche of funding for Clean Aviation as it's called now, over 700 million euros for that one launch of the program. Again, over the full period of the program will be around 5 billion Euros. And that has achieved the 4.4 billion we spent in Clean Sky Two. Has achieved a huge amount to drive this agenda forward.

Guy Norris:

And I think one thing that probably bears repeating in a way, again contrasting with previous ISABE meetings, is the doubling down on hydrogen, I think, as a topic. I know that there was a bit of a dichotomy, certainly in Europe, it's been a big focus now ever since Airbus really announced its plan to develop a sustainable hydrogen-fueled airliner targeting 2035. But, I think since then we've seen the US come more aboard as well. Even Boeing has started to talk about the potential for it. So, one of the things that intrigued me was listening to some of the technical sessions here where you have people from Cranfield particularly actually showing early results from hydrogen combustor work with micromix combustor designs. Things like that, which, again, I know I'm harping on here, but you would never have seen that just a couple of years ago. And I think that's fascinating.

Ric Parker:

Hydrogen has certainly come to the fore. As you say, people have been talking about it for years, but suddenly... I mean the Airbus announcement of their three concept aircraft for mid-range single aisle replacement did a lot to stimulate the thinking and frankly did a lot to inspire young people to say, "oh, this is different. Yeah, that's a bit of the industry I want to get involved in." And we saw today, over this week, as you say, most universities, but certainly at Cranfield, a very strong team here filling an entire conference session with their work on hydrogen and some of the good stuff they're doing. And that's all driving in the right direction. Just last week, a good friend of mine at Cambridge University sent me the results of something they've done on hydrogen combustion.

That's one of the issues. So, you can burn hydrogen in a gas turbine engine just like we burn kerosene today. You may not publish this bit, but I always say gas turbines can work on everything from chicken shit to hydrogen, and anything in between. But, feel free to cut that out.

But hydrogen does have its own interesting things. It's got a very high flame temperature. It's got very high flame speeds. So, you don't get these big long flames. The flame burns within a few centimeters of the burner and you have to get that energy out in a very short time. You have to get the air in. So, it needs a very different burner. They're not just a spray of fuel and the oxygen comes in and finds it somewhere like in a conventional burner. The oxygen and the hydrogen have to meet each other very close to that surface, and it goes in through a lot of tiny orifices and it's really exciting.

And then you've still got- Lots of people say, "Oh, hydrogen, totally clean." Well, no carbon, but you're frying the air at an even higher temperature. And that's what makes nitrous oxide and nitric oxide, which do have a contribution to global warming, but they're also really nasty for local air quality, particularly around airports. So, getting that down to at least the levels we used to with kerosene in a hydrogen burner is a whole new challenge when again, people have been talking about water injection and other ways of doing that this week.

Guy Norris:

And I get the feeling that we're very much at the beginning of a long phase. Or at least an intense phase. We can't afford it to be too long, obviously, but of research into so many new areas, particularly with hydrogen, as you said, and every aspect of the infrastructure all the way down to combustion as well as research into contrail impacts at altitude, so on and so forth, across the waterfront. But just as equally, we're also looking at hydrogen fuel cells. There's a lot of discussion about battery electrics. To the point where I'm thinking, does ISABE need to adapt its title at some stage,

Ric Parker:

Air breathing may become a bit limiting, but at some level, if it's still got a propeller on the front, even if all the motor is electric, then you can more or less say it's still breathing in the air and pushing it out the back with a bit more energy it took it in.

Shaji Manipurath:

And the motor has to be colder.

Speaker 3:

It's got to be cool, exactly.

Ric Parker:

Batteries have to be cool and the hydrogen tanks certainly have to be cool.

Shaji Manipurath:

I just want to add one thing, as well. The aviation sector can actually... Things like hydrogen have been used in other sectors and even gas turbines, industrially speaking, have been utilizing hydrogen as a fuel in very niche markets. So, things like gas turbine combustion, a lot of technology has been developed for the industrial market, I think, that can be brought into the aviation space, and that's one way to accelerate, I think, this whole development cycle that we have.

Guy Norris:

Perhaps from your perspectives, was there one particular highlight of the conference? I know we've still got one day to go, but something that kind of made you sit up and think, "Gosh, this is a changing time," sort of thing.

Ric Parker:

I think this morning we had a presentation from Bauhaus, and this is a little think tank just outside Munich. I've been close to it for many, many years. It was set up quite a few years ago and the first CEO of Bauhaus used to be my counterpart as CTO at MTU Engine Company and they've always come up with these radically different ideas and just made people stop and think, "Oh gosh, that looks different, that sounds different." And, "Hey, how's that going to work?" And they don't always know the answers to those. They're just great people at thinking up ideas. But we saw today just the amount of calculations and work this team of about 50 people have put behind those, and some of them will make it through, and there were some wonderful ideas there.

But if I can have a second thing that take away from this conference, then, the thing that really always inspires me about ISABE meetings, we put a lot of effort into getting young people to come along. There's a lot of PhD students, many of them presenting their first ever papers. Standing in front of somewhat daunting of a very senior audience in many cases. But we bend over backwards to encourage companies to send them along. We give them very reduced fees so they can afford to come. And it's always a great place to meet these young people and to hope they stay with our industry and develop with it. So we definitely... They're our future. I keep trying to retire. We need people to come in and do the work going forward. And I'm really impressed with the quality of these young people, the enthusiasm they have for the industry. And that matches up with the quality of speakers we're able to expose them to. So, 17 keynote speakers, most of them thought leaders from the industry. So, that fusion of bright young people and people who've been around in this industry and really understand it is great.

Speaker 3:

Yeah, absolutely. Shaji, any thoughts?

Shaji Manipurath:

Yes, my main takeaway is it's really hard to organize a conference.

But apart from that, I would say that it's really interesting to see how sustainability has now become the number one driver in a lot of the technology advances in our sector. I think it always has been, to some extent. But more than ever, all the great ideas that we are working on are so complex and so challenging, ranging from how do you bring an onboard hydrogen into the aviation infrastructure, all the way to fuel cells and advanced concepts and boundary layer ingestion. I think they're tremendous opportunities for young professionals getting into the field. For all researchers to get into new research areas. So, I think we are in a very exciting revolution in the industry and I think ISABE has led the way and will be leading the way into the future.

Guy Norris:

Well, that's a wrap for this week's Check 6. Don't miss the next episode by subscribing to Check 6 wherever you listen to podcasts. And one last request. If you're listening in Apple Podcasts and want to support this podcast, please leave us a star rating or write a review. Bye for now.