Bombardier is offering a glimpse at what it thinks could be the future of business jets: a blended-wing body design that forms a key part of its new Eco Jet sustainability initiative. Yesterday at EBACE 2022, the Canadian airframer revealed a small-scale model it has been using for extensive flight and wind-tunnel testing as it seeks to refine the technology it views as integral to its long-term product strategy.
In the shorter-term, the company (Booth Z117, Static AD_15) is also employing this model as a testbed for improvements that could be introduced more incrementally to existing aircraft.
While details of the development are still very much in the works or under wraps, Benoit Breault, Bombardier’s director of research and technology, told AIN that the blended-wing concept is “a key part of our strategic thinking.” The company’s engineering brain-trust sees the aerodynamic improvements promised by the new wing as being one of three pillars to support its ambitions to reduce business aviation's carbon emissions. Switching to using sustainable aviation fuel and adopting new propulsion systems such as hydrogen, hybrid-electric, and all-electric power sources round out the other two pillars.
For now, Bombardier remains agnostic about what direction it might take for the propulsion system of a next-generation business jet. Breault indicated that the company is already in talks with several leading engine manufacturers about how the blended-wing architecture might accommodate next-generation propulsion systems.
“Our approach has been to think about what our portfolio of products should and could look like 30 years from now, and then backtrack to determine what technologies we need to achieve that, with a carte blanche in terms of options to be considered,” Breault explained.
His strategic technologies office is advancing a diverse portfolio of research programs, tasked with ensuring that the Canadian airframer can achieve the technology readiness levels required to progress. In concert with that, a conceptual design team looking at what the aircraft of the future could look like.
“Some of the work is at the concept stage, but in other cases, it is in a development timeline that could lead to technology finding its way onto other [existing] aircraft programs,” Breault said. “We have to deliver technology for the short, mid, and long terms, and try to strike a balance from an investment point of view so that we are feeding the short- and medium-term objectives.”
The Bombardier team, which Breault said has deep expertise in aerodynamics, began its work on the blended-wing concept more than a decade ago when a couple of engineers started projecting future needs and possibilities. With one eye on existing military aviation interest in blended 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 work protected under patents. A scale model, at just 7 percent of the size of Bombardier’s Global family of long-range aircraft, has been flying for the past three years in secret in Quebec.
The company is now building a model that will be around twice the size of the unit on display this week at EBACE and expects to start flying it at the same remote location in Quebec over the next six to 12 months. “This will give us greater precision in our data collection,” Breault explained, adding that the work should get Bombardier closer to its aim of achieving TRL 6. A TRL 6 technology has a fully functional prototype or representational model, while the ultimate goal is TRL 9, indicating a technology is "flight-proven."
In this next phase of work, Bombardier also plans to further explore possible designs for future business aircraft. It will also advance its evaluation of new propulsion systems, which could include hybrid-electric and distributed electric technology.
Building on early work with the blended-wing architecture, the company will also step up work on new avenues for aerodynamic improvements. Breault said this will include novel boundary layer injection techniques to reduce drag in the tail section by slowing down the boundary layer of air along the airframe. “If we can re-energize this speed to one that matches the speed of the aircraft, we will reduce the drag in a way that is very novel for business aircraft,” he said.
Bombardier’s reasoning for taking a multifaceted approach to driving down business aviation's carbon emissions is to do everything possible to ensure that this special mode of transportation maintains its advantages for end-users as it gets greener.
“We believe passengers will have to make some compromises to fly sustainably,” Breault told AIN. “For example, using hydrogen fuel [for direct propulsion in engines] could need enormous cryogenic tanks, but passengers probably won’t want to compromise on the size and comfort of their cabins. What brought us to the Global 7500 were [the goals of flying] farther, faster, smoother and more connected, but we believe we can achieve both passenger comfort and social and environmental responsibility.”
Part of Bombardier’s focus for work aimed at short- and mid-term applications is on the electrification of existing aircraft subsystems. For instance, it is evaluating possibilities such as using hydrogen fuel cells to replace the ram air turbines that provide emergency power in the event of an engine failure.
The company is also looking to introduce digital-twin technology that creates an exact replication of systems, using updated real-time data, and using simulation, machine learning, and artificial intelligence to support decision-making. Breault said this approach has already been adopted for health monitoring for the Global 7500 and is now set to be expanded for other Bombardier aircraft and engine data.
“It is too early to say for sure that technology like the blended wing is definitely future [of business aircraft] but we are positive that we can mature it,” Breault concluded, while acknowledging the risks entailed.