Bombardier offers a glimpse into what it believes could be the future of business jets: blended wing body design, which is a key part of its new Eco Jet sustainability initiative. Yesterday at EBACE 2022, the Canadian aircraft manufacturer unveiled a small-scale model that it has used for extensive flight and wind tunnel testing as it seeks to refine a technology it considers integral to its long-term product strategy.
In the short term, the company (Booth Z117, Static AD_15) is also using this model as a testbed for improvements that can be gradually introduced to existing aircraft.
Though development details are still in the works or under wraps, said Benoît Breaux, director of research and technology at Bombardier. Ain that the blended wing concept is “a key part of our strategic thinking”. The company’s engineering think tank lists the aerodynamic improvements promised by the new wing as one of three pillars supporting its ambition to cut carbon emissions from business aviation. The transition to cleaner aviation fuels and the introduction of new propulsion systems such as hydrogen, hybrid-electric and all-electric power sources complement the other two pillars.
For now, Bombardier remains unconcerned about which direction the next-generation business jet propulsion system might take. Brough indicated that the company is already in discussions with several leading engine manufacturers about how the blended wing architecture can accommodate the next generation of propulsion systems.
“Our approach has been to think about what our product portfolio should and could look like 30 years from now, and then go back to determine what technologies we need to achieve that, with flame in terms of options to consider,” Bro explained.
Its Strategic Technology Department promotes a diverse portfolio of research programs to ensure that the Canadian aircraft manufacturer can achieve the levels of technology readiness needed to advance. Alongside this, a group of concept designers are exploring what the aircraft of the future might look like.
“Some of the work is at the concept stage, but in other cases it is on a development timeline that could lead to the technology finding its way into other areas. [existing] aviation programs,” Bro said. “We need to deliver technology for the short, medium and long term and try to strike a balance from an investment perspective so that we meet short and medium term goals.”
The Bombardier team, which Breo says has deep knowledge of aerodynamics, began work on the blended wing concept more than a decade ago when a pair of engineers began to anticipate future needs and opportunities. Given the existing military aviation interest in mixed wings, they also launched research programs with several key universities.
At this point, the company believes the work is somewhere between technology readiness levels (TRL) 3 and 4, with some initial wind tunnel testing successfully completed and the work protected by patents. The scale model, just 7 percent the size of Bombardier Global’s long-haul aircraft family, has been secretly flown in Quebec for the past three years.
The company is currently building a model that will be roughly twice the size of the model unveiled this week at EBACE and plans to launch it at the same remote location in Quebec over the next six to twelve months. “This will give us more accuracy in data collection,” Bro explained, adding that the work should bring Bombardier closer to achieving the TRL 6 goal. TRL 6 technology has a fully functional prototype or representative model, and the ultimate goal is TRL 9, indicating that the technology is “flight-proven”.
In the next phase of work, Bombardier also plans to continue exploring possible designs for future business jets. He will also advance his assessment of new powertrains, which may include hybrid-electric and distributed electric technologies.
Building on early work with the blended wing architecture, the company is also intensifying work on new aerodynamic improvements. Bro said this would include new boundary layer injection techniques to reduce tail drag by slowing down the boundary layer of air along the airframe. “If we can increase that speed to match the speed of the aircraft, we will reduce drag in a way that is very new for business jets,” he said.
The reason Bombardier is taking a multi-faceted approach to reducing business aviation carbon emissions is to ensure that this special mode of transport maintains its end-user benefits as it becomes more sustainable.
“We believe that passengers will have to make some compromises in order to fly greener,” Broe said. Ain. “For example, the use of hydrogen fuel [for direct propulsion in engines] huge cryogenic tanks may be required, but passengers probably won’t want to compromise on the size and comfort of their cabins. What brings us to the Global 7500 is [the goals of flying] further, faster, smoother and more connected, but we believe we can achieve both passenger comfort and social and environmental responsibility.”
Part of Bombardier’s short-to-medium-term work is focusing on the electrification of existing aviation subsystems. For example, it is evaluating options such as using hydrogen fuel cells to replace ram air turbines that provide emergency power in the event of an engine failure.
The company is also looking to implement digital twin technology, which creates an exact replica of systems using real-time updated data and uses modeling, machine learning and artificial intelligence to support decision making. Bro said this approach has already been adopted to monitor the health of the Global 7500 and will now be extended to other Bombardier aircraft and engine data.
“It’s too early to say for sure that technologies like mixed wing are definitely the future. [of business aircraft] but we are confident that we can mature,” concluded Breo, while acknowledging the associated risks.