In sight of electric flight

ANSYS’ aerospace & defence global industry director, Paolo Colombo looks at why simulation is critical to make electrification the norm in the aerospace industry.

The electrification of transportation industries is not new or shocking news. Automotive engineers have amped up development of electric powertrains for over a decade. However, the aerospace industry is late to jump onto this trend, both because the technology to build the small, light high-power systems needed on an aircraft is still not ready, particularly on the battery side, and because we don’t have enough flight experience to be sure we can certify these systems according to the strict aerospace safety standards. However, we don’t have the time to gradually build confidence in this technology through slow and expensive flight tests. If organisations want to keep up with their competitors and comply with the incoming rules on pollution and noise emission, then electrification needs to be an important part of their business strategy. The industry needs to speed up innovation by managing risks faster and economically.

The MEA philosophy

The development of a ‘more electric aircraft’ (MEA) is essentially replacing traditional pneumatic, hydraulic and mechanical aircraft systems with electric and electromechanical ones. While this is an incremental innovation, already partly applied on flying airplanes, we are looking to the next step — the electrification of propulsion. In its full electric or hybrid configuration, electric propulsion will be the key for a future more quiet, efficient and environmentally friendly aircraft. When we’re likely to see this become mainstream will depend on how much we are able to innovate on batteries, motors, inverters, and power electronics.

Engineers are currently facing huge challenges as they need to design and validate components that must be as light and compact as possible, but at the same time manage high power, so these components are prone to overheating problems. However, this complexity can be well managed through simulation. The ANSYS simulation platform provides a comprehensive solution for electrification. It allows engineers to design all the main components of the electrical system (generators, accumulators, inverters, bus bars, electric motors and actuators, power electronics and control software, and semiconductors) through specific tools and proven workflows, and look at them in a multiphysics dimension. Engineers can also then evaluate the interacting effects of physical phenomena like currents, heat (and cooling), mechanical stresses and deformations, electromagnetic interferences, losses and so on. And it’s possible to do it for both a single component or for the whole system, evaluating what happens when we integrate it all.

Many companies are already investing in the electrification of aircraft and, while the day in which we will fly on an electric aircraft seems like a long way away, we are already seeing a lot of applications in the short term: drones are already mostly flying electric, and there are flying technology demonstrators of general aviation aircraft, urban air mobility vehicles (UAM) and high-altitude platform stations (HAPS).

Taking flight

Although there is still a way to go for fully electric flights in the aerospace industry, aerospace companies are still leading in the way in new, innovative technology. Metal additive manufacturing is already being used in aerospace due to its ability to reduce cost and production time.

Additive manufacturing also reduces the number of parts needed to build an aircraft. For instance, one company printing a fuel nozzle and was able to reduce the number of parts needed from 20 parts to one part. The benefit is huge. You have to manage a single CAD file instead of 20, build the part through a single process, avoid assembly (which uses cost and time, plus it adds failure points), decrease the number of parts in stock and decrease maintenance costs. The problem with additive manufacturing is that machines bring a lot of stresses to the built part, and this leads to unpredictable deformations and possible weaknesses. ANSYS simulation capabilities include a specific additive manufacturing tool that helps to predict these stresses and deformations, allowing companies to build the part right the first time. A huge saving of time and money.

Optimising your designs

Understanding electrification in the aerospace industry can be a struggle, but simulation is the most economical way to overcome this struggle and teach aerospace companies to envision how they will electrify their complex systems.

These companies are often stuck in their traditions, building test rigs called iron birds that are used for testing and implementing prototype hardware. Of course, this method is extremely common and safe, but market demands are changing, and companies can no longer keep up with making physical prototypes. In order to innovate, the aerospace industry needs to manage risks faster and more economically, which is where simulation comes into play.

Simulation allows engineers and design teams to explore scenarios and theories that cannot be reproduced in a physical test, or, at least, cannot be reproduced easily and cost-effectively. Engineers are also able to add hardware and software into the development loop. The control software is particularly critical as it manages the system and has a major influence on its performances. It’s important to be able to test the software and the systems together. Coding is also a critical task: aircraft today are using millions of lines of software that must be written, debugged and certified. This can be all done using ANSYS embedded software capabilities with the ANSYS SCADE suite. The tool can prototype the code, and then self-generate certified code according to DO 178-C standard. Engineers can then use this control code, as well as physical hardware and simulations, to verify the full behaviour of their system, meaning engineers can understand phenomena and optimise their design accordingly without panicking about failing too late in the design process or wasting money.

The long haul

Can we replace all physical testing with simulation? The answer to that is simply, no. At least, in most cases. What simulation provides is the flexibility to predict the behaviour of a system in many conditions, including those that are difficult to replicate like ice. And it’s possible to run thousands of these simulations in a short time and for a fraction of a cost of a physical test. This means that engineers can try a lot of ideas, even unconventional ones, and gain insight on the product’s best design and the physical phenomena that are influencing the performance. By using simulation, you can be confident that the physical test, usually performed as a final validation or at a key milestone in the development phase, will work as expected.

The aerospace industry, however, currently has an electrical simulation adoption gap. Aerospace companies understand the importance of innovative technology in their industry (they use simulation mostly to model fluid dynamics and structural mechanics), but there is still more that can be done, starting with a stronger culture of simulation and multiphysics simulation platform adoption.

Simulation solutions like that from ANSYS help aerospace and defence product development teams meet their key business initiatives through simulation-driven aerospace engineering design, and drives innovation by letting teams explore a wider range of product design options. Leveraging the power of aerospace design software can help companies meet the challenges of electrification, light weighting and aerodynamics, thereby improving fuel efficiency, reducing environmental impact, and satisfying customer demands for safety, reliability, faster time to market, and design for affordability.

The global aerospace industry faces many critical challenges around engineering and technology but if it wants to win on electrification, simulation is the key.

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