Redesigning the Systems Engineering Process to Speed Development of E-Propulsion Aircraft

The e-propulsion aircraft industry is a hotbed of activity and investment. However, converting these exciting concepts into viable commercial solutions presents one of the most significant challenges in the history of aviation. To streamline the development process and accelerate time to market, OEMs should consider replacing traditional, silo-based approaches to systems engineering with a model-based strategy that facilitates seamless, real-time collaboration among the entire development team.

Until the unwelcome intervention of the coronavirus pandemic, the civil aviation sector was benefiting from sustained growth in demand for global air travel. At the time of writing, it is hard to predict how quickly the industry will return to normal, and indeed what normal will look like. However, even amidst unprecedented levels of uncertainty, there can be little doubt that electric propulsion will be critical in shaping the future of aviation. Indeed, given that easing gridlock is central to the urban air mobility offer, it could be argued that the pandemic has at least given us a glimpse of what a congestion-free, clean air future might look like.

While much progress has already been made in terms of developing electric and hybrid electric propulsion systems, significant challenges remain if we are to transform exciting concepts and prototypes into viable commercial solutions for transporting people and cargo. In overcoming these hurdles quickly and cost-effectively, OEMs can realize significant benefits by adopting a radically different approach to the system design process. By shifting from traditional, silo-based methodologies to a philosophy built around a single, system-level model and efficient real-time collaboration among the entire development team, it becomes possible to eliminate long-standing bottlenecks and inefficiencies in the delivery of complex products.

Fierce Competition Ahead

Even for those involved in the aerospace industry, the size and scale of the electric aviation sector can come as a surprise. Recent reports indicate that there are over 200 manufacturers active in this field, backed by total investments that already run to billions of dollars. The extent of the interest is best explained by the potential rewards on offer. By 2040, it is estimated that the U.S. eVTOL (electric vertical takeoff and landing) market alone will be worth $17.7 billion.

Inevitably, the competition between players that range from household names such as Airbus and Uber to ambitious start-ups, is going to be fierce. To come out on top, enterprises will need to resolve some seriously demanding issues. These include the ability to volume-manufacture affordable products and achieve range/payload capabilities that offer owners and operators a realistic return on investment. Safety is naturally paramount; in particular, there is a pressing need to secure wider public confidence.

Complex Projects Expose Weaknesses

Given such pressures, there are convincing arguments in favor of OEMs taking an opportunity to rethink their approach to systems engineering. To date, in the aviation sector and beyond, it is still sometimes characterized by a series of distinct boundaries: for example, between the various stages in the product development lifecycle, and different disciplines. And even the most streamlined systems engineering processes are often undermined by problems in the transition between 1D and 3D design models.

Unfortunately, the increasingly complex nature of systems engineering has served to highlight these weaknesses. If each element of the design is handled discretely, there is obvious potential for miscommunication and misunderstanding; the wider implications of changes made in one area are not automatically reflected and registered in others. Moreover, at every stage, time is being lost. Lessons learned by one team are not readily available to others. As each new step begins, there is a manifest risk that the wheel is being reinvented.

The Benefits of a ‘V-Shaped’ Development Path

Figure 1. The V-Model approach to design

Figure 1 shows the widely employed V-Model approach to design. The left-hand side of the V represents the digital element of the design process. The right-hand side reflects the physical validation journey assisted by physical simulations, through to product release and manufacturing.

Virtually all aerospace OEMs have implemented this V-Model in some form or other. The starting point, at the top left of the V, is where mission requirements for the product are established. These are then translated to vehicle functional requirements using model-based systems engineering (MBSE). The process then cascades down to system, subsystem, and component design. Such a process leads to a shorter development cycle and enhanced product design.

Unfortunately, many processes that utilize the V-Model are compromised by a lack of ability to transition from 1D to 3D models. The process starts at the top left of the V with a 1D model. Ideally, it should generate increasing content for the 3D model as it progresses further down the left-hand side. To fully leverage the efficiency of the V-Model, it is essential to have a setup that enables 1D and 3D content to co-exist in the same model, and for them to be easily interchangeable. Digital models of fully validated products should also transition seamlessly to digital twins for the products deployed in service. These can then help with predictive maintenance, failure prediction, and assessment of remaining useful life throughout the lifetime of the product.

Figure 2. An existing design is often used as a starting concept to build 1D models.

Model-Based Systems Engineering

The strategy is rooted in the principles of MBSE. In simple terms, this applies the model-based approach that is now the norm for mechanical and electrical design to systems-level engineering. So instead of a plethora of different files, documents, and discrete models, a universal, system-level model becomes the ‘Authoritative Source of Truth.’ With everyone involved working to this common model, it becomes far easier to ensure that collaboration, knowledge sharing, and a seamless end-to-end development cycle become part of the project DNA.

United States Naval Air Systems Command Leads the Way

Figure 3. 3D CFD analysis was performed at a system level.

The United States Naval Air Systems Command (NAVAIR) has emerged as a pioneer in this field. Its Systems Engineering Transformation (SET) initiative aims to put in place the foundations for effective collaboration between government and industry in model-based acquisition. Altair has been selected to help implement this framework and prove it on a surrogate product. This facilitates a fully integrated multi-physics approach and effortless transition between 1D and 3D design.

Overcoming Inertia

Figure 4. 3D Structural Systems Model: CFD loads were used to perform 3D structural analysis.

The SET initiative serves to demonstrate that, in technical terms, all the necessary building blocks are in place to enable a more seamless, collaborative approach to system design. In fact, at Altair it is a trend being supported right across the design engineering industry. In practice, the real barriers to wider adoption of an MBSE-type strategy are now more likely to lie in cultural and organizational inertia. People have become accustomed to doing things a certain way and are naturally reluctant to implement what appear to be dramatic changes.

In this context, it is worth stressing that a wholesale, top-down approach to change is not the only option available to OEMs. It is equally feasible to follow a more evolutionary pathway, fueled from the bottom up by design teams adopting software tools that enable cooperation at a grass roots level. That way, change becomes an ongoing, organic affair that can and should spread throughout the product development cycle.

Time To Innovate

Figure 5. Results from the global analysis were cascaded down to do detailed design.

Not long ago, concepts such as the eVTOL taxi were the stuff of science fiction. Now, making these bold ideas a commercially viable reality is a pressing imperative if the aviation industry is to meet its environmental obligations. To ensure success, leadership teams need to consider all the options available to streamline development and speed time-to-market. An MBSE-based approach, enabling real-time collaboration and seamless transition between 1D and 3D models, offers unprecedented opportunities to do just that.

In the aerospace industry, innovative thinking is invariably the key to achieving landmark breakthroughs. The electric aviation sector will be no exception. Enterprises that apply it to the system engineering process, as well as the products themselves, will be ideally positioned to secure a significant competitive advantage in what is now the industry’s most important and exciting emerging market.

This article was written by Dhiren Marjadi, VP Global Aerospace Business, Altair (Troy, MI). For more information, visit here .