Periodic Reporting for period 2 - TRADE (Turbo electRic Aircraft Design Environment (TRADE))
Período documentado: 2019-03-01 hasta 2020-06-30
"The ever-increasing amount of air travel and transport calls for substantial improvements in aircraft fuel efficiency and emissions. To reach such goals, the underlying concepts of aircraft must be reinvented. Local infusion of technology, for instance geared turbo fan technology on the power plant, is not enough. This improvement potential is nearly depleted as Overall Pressure Ratio and fan diameter can only be mildly increased. In case of the former, reasons include HPC efficiency and NOx formation, in case of the latter, issues include nacelle weight and drag, or unducted fan noise. Several alternatives have been proposed. One of them is the electrification of primary power, which was analyzed in this project. Primary power, also called thrust, is generated by the jet engines on today's aircraft and propels the aircraft. Aircraft with partially or fully electrified primary power systems are called hybrid or fully electric aircraft. Here, electrical fans, light-weight power electronics, efficient energy distribution and reliable gas turbine cores for electrical power generation are combined into a new aircraft architecture. A first objective of this project was to build sufficiently detailed, physics-based and rubberized engineering predictions for key disciplines of such architectures (""modeling and simulation"") and make them available to specific stakeholders in research and academia to complement their aircraft design platforms with previously missing elements (as, e.g. large electrical power systems were not part of aircraft design with conventional architectures). A second objective was the development of a simple verification platform to conduct virtual aircraft design and integration using these electrified propulsion concepts, which allowed stress-testing the previously mentioned engineering predictions per discipline and generating meaningful predictions on how aircraft with this new technology would perform. The third and final objective was the use of the verification platform in the analysis and comparison of potential future electrified aircraft against their future counterparts not using electrified propulsion."
Addressing the first objective, the TRADE project consortium worked on the engineering predictions for three new aspects in aircraft conceptual design. First, an advanced structural model quantifies the impact of the installation of heavy equipment on the sizing of the aircraft structure. Second, refined onboard system models capture design and performance trades in electric power systems coupled with gas turbines. Third, a thermal management module predicts how extensive systems beyond the conventional air conditioning and pressurization of the cabin affect the aircraft. All these parts were embedded in operational and mission models enabling flight dynamic analyses. In all this work, the definition of inputs and outputs of the different modules were a key achievement and the development and maturization of the rubberized engineering predictions themselves. Here, the consortium members built on their extensive model assets and deep system understanding. The engineering predictions were first delivered in 2018 to specific stakeholders. At project closure, more than half of the developed models are available in improved variants in existing software products offered by the consortium and the remainder are being integrated. Like this, the key project outcome is not only available to specific stakeholders but available generally. This is also a key exploitation area.
With respect to the second objective, the integration of the engineering prediction modules was achieved via the verification platform. Thanks to the incremental improvements implemented in the project, this platform also enables gradient-based optimization with analytic derivatives leading to faster and more robust converence in the aircraft studies.
Finally, and with respect to the third objective, the project also delivered studies into both electrified aircraft configurations specified for the project, the boosted turbofan and the distributed propulsion. These were assessed at subsystem as well as whole-aircraft level. The boosted turbofan for instance leads to a fuel burn reduction of 1.4% with current technology and 3.5% with future technology (assumed entry-into-service 2035, cited benefit on business case block fuel net reduction). Results were so far published in seven peer-reviewed scientific publications in journals and at conferences. Eight pieces of other communication were released during the project. Some of the last results of the project have not even been disseminated yet and therefore the partners continue publishing about the project results even after its formal closure.
With respect to the second objective, the integration of the engineering prediction modules was achieved via the verification platform. Thanks to the incremental improvements implemented in the project, this platform also enables gradient-based optimization with analytic derivatives leading to faster and more robust converence in the aircraft studies.
Finally, and with respect to the third objective, the project also delivered studies into both electrified aircraft configurations specified for the project, the boosted turbofan and the distributed propulsion. These were assessed at subsystem as well as whole-aircraft level. The boosted turbofan for instance leads to a fuel burn reduction of 1.4% with current technology and 3.5% with future technology (assumed entry-into-service 2035, cited benefit on business case block fuel net reduction). Results were so far published in seven peer-reviewed scientific publications in journals and at conferences. Eight pieces of other communication were released during the project. Some of the last results of the project have not even been disseminated yet and therefore the partners continue publishing about the project results even after its formal closure.
State of the art: Advanced modelling was originally available for conventional high bypass ratio engines, electrical power systems, and thermal management systems in isolation.
Identified gaps: When the original state of the art modelling of hybrid propulsion systems is considered, limitations existed in the development and adaptation of models dedicated to specific components for such advanced future engine architectures. Hence the multi-disciplinary effects of a combination of radical components (electrical motors, converters/transformers, cables, energy storage, electrical fans, super-conductivity, cryo-coolers etc.) on integrated solutions had not been considered.
Progress beyond the state of the art: In order to progress from existing modelling capability and to adequately assess performance (in terms of thrust capabilities and block fuel consumption) at a preliminary design stage, reliable and robust models were developed. These models are capable of establishing the design impact of the novel components on the aircraft and propulsion system weight, life, overall mission fuel burn and environmental emissions (CO2) and direct operating costs for the aircraft.
A customised multi-disciplinary design framework with the integrated models was used to create design space maps. It was used to optimise the hybrid propulsion system, establishing the link between the thermal power part and the electrical power part, while assessing the effect of component losses and their dependencies to key design parameters. The framework was then used to undertake mission level performance optimisation of individual components and the integrated system while considering dimensions, weight, drag and engine uninstalled/installed performance.
The integration of model assets like Modelica libraries on gas turbines, electrical power systems, and thermal management including cooling provided significant progress beyond state-of-the art with respect to the modelling of new enabling technologies, more robust models and a more robust integration framework and a broader range of design space exploration and multi-disciplinary optimisation studies.
With the model-based design platform suggested by TRADE, the aircraft sub-system models were interfaced for the first time from their “native modelling language” with full expressivity required to cover this wide domain to a native aircraft conceptual design environment enabling full system level MDO.
Equally important to the development of new or extended component models, the unconventional system analyses within TRADE provided additional cases, on which the engineering predictions were evaluated and improved further.
Identified gaps: When the original state of the art modelling of hybrid propulsion systems is considered, limitations existed in the development and adaptation of models dedicated to specific components for such advanced future engine architectures. Hence the multi-disciplinary effects of a combination of radical components (electrical motors, converters/transformers, cables, energy storage, electrical fans, super-conductivity, cryo-coolers etc.) on integrated solutions had not been considered.
Progress beyond the state of the art: In order to progress from existing modelling capability and to adequately assess performance (in terms of thrust capabilities and block fuel consumption) at a preliminary design stage, reliable and robust models were developed. These models are capable of establishing the design impact of the novel components on the aircraft and propulsion system weight, life, overall mission fuel burn and environmental emissions (CO2) and direct operating costs for the aircraft.
A customised multi-disciplinary design framework with the integrated models was used to create design space maps. It was used to optimise the hybrid propulsion system, establishing the link between the thermal power part and the electrical power part, while assessing the effect of component losses and their dependencies to key design parameters. The framework was then used to undertake mission level performance optimisation of individual components and the integrated system while considering dimensions, weight, drag and engine uninstalled/installed performance.
The integration of model assets like Modelica libraries on gas turbines, electrical power systems, and thermal management including cooling provided significant progress beyond state-of-the art with respect to the modelling of new enabling technologies, more robust models and a more robust integration framework and a broader range of design space exploration and multi-disciplinary optimisation studies.
With the model-based design platform suggested by TRADE, the aircraft sub-system models were interfaced for the first time from their “native modelling language” with full expressivity required to cover this wide domain to a native aircraft conceptual design environment enabling full system level MDO.
Equally important to the development of new or extended component models, the unconventional system analyses within TRADE provided additional cases, on which the engineering predictions were evaluated and improved further.