Aircraft Design for the Electric Revolution
H. Tummescheit, Modelon
As the use of fossil fuels in other transport sectors declines, the aerospace community starts to embark on one of the most fundamental engineering challenges of the last decades, the hybridization and electrification of flight. Technically, this corresponds to the electrification of primary power. Primary power is generated by the jet engines on today’s aircraft and propels the aircraft. Thrust is a synonym for primary power. Aircraft with partially or fully electrified primary power systems are called hybrid or fully electric aircraft. The available product design methodology and software is applicable to such problems only to a limited extend, as the disciplines in classic aircraft sizing and design do not contain high power electric sub-systems, turbo-electric or gas turbine-driven generators, and extensive energy storage devices.
We propose an aircraft and sub-system simulation and design framework for such applications. It is based on three main components:
- a variant of the open source Modelica compiler jmodelica.org,
- a set of existing and tightly integrated Modelica Libraries for aircraft design, which are extended for the electrification of flight
- and the open source optimization framework OpenMDAO.
Based on the Modelica object-oriented and acausal modeling language, we believe that it becomes possible to tightly integrate the three aspects of aircraft, engine, and sub-systems. One of the critical ways to achieve framework flexibility is through mixing handbook and physics-based models. We define handbook methods or models through their reliance on statistical correlation of key design aspects based on databases of conventional designs. An important example of handbook methods is the classic literature on aircraft design. Physics-based methods in turn rely on first principles such as conservation equations of mass, energy, and momentum. Obviously, the latter are suitable for studying unconventional designs, while the former are not. Like this, the framework allows mixing physics-based models for unconventional system aspects with handbook methods for everything around them. This is facilitated using so-called layered architectures.
The presentation will describes requirements, and key aspects of the selected methodology and implemented solution. It is a presentation reporting work in progress in an on-going research project, and contains only limited preliminary results.