Multidisciplinary design optimisation of a fully electric regional aircraft wing with active flow control technology

Abstract

The German research Cluster of Excellence SE2A (Sustainable and Energy Efficient Aviation) is investigating different technologies to be implemented in the following decades, to achieve more efficient air transportation. This paper studies the Hybrid Laminar Flow Control (HLFC) using boundary layer suction for drag reduction, combined with other technologies for load and structural weight reduction and a novel full-electric propulsion system. A multidisciplinary design optimisation framework is presented, enabling physics-based analysis and optimisation of a fully electric aircraft wing equipped with HLFC technologies and load alleviation, and new structures and materials. The main focus is on simulation and optimisation of the boundary layer suction and its influence on wing design and optimisation. A quasi three-dimensional aerodynamic analysis is used for drag estimation of the wing. The tool executes the aerofoil analysis using XFOILSUC, which provides accurate drag estimation through boundary layer suction. The optimisation is based on a genetic algorithm for maximum take-off weight (MTOW) minimisation. The optimisation results show that the active flow control applied on the optimised geometry results in more than 45% reduction in aircraft drag coefficient, compared to the same geometry without HLFC technology. The power absorbed for the HLFC suction system implies a battery mass variation lower than 2%, considering the designed range as top-level requirement (TLR).

Vehicle Technologies towards Sustainable and Energy Efficient Aviation

“…The outputs are considered in terms of data look-up tables, surrogate models, or tool exchange, which were directly integrated with the design framework. The final design of the short-range aircraft includes a clean sheet sizing, low/medium-fidelity MDO [5], and physics/based design optimization for refinement [6]. The final design assuming a 2050 EIS is shown in Fig.…”

“…Although the Covid-19 crisis has led to a significant drop in global air travel, it is expected that the megatrend "Mobility" will generate significant demands for air transport capacities in the near future. In 2015, transportation alone accounted for 23% of the worldwide, anthropogenic CO 2 emissions, with aviation being responsible for 12% of the transport-related CO 2 emissions 6 . Even assuming that typical total growth rates in commercial air transport volumes of 4% to 5% -as seen during the last decades -based on the pre-Covid-19 level will not be caught up the next years, the challenging targets on environmental protection of at least an 80% reduction in greenhouse gas emissions by 2050, as set by the IPCC requires revolutionary changes in aviation.…”

“…Multiple aircraft configurations were sized and the best one, i.e., the one with minimum energy consumption, is selected for further analysis and refinement. The final design includes a clean sheet sizing, low/medium-fidelity MDO [5], and physics/based design optimization for refinement [6]. Fehler!…”

The Suction Panel - xHLFC and Structural Solution for Energy Efficient Aviation

“…Drag benefits vs. system weight increase In order to operate the compressor of the HLFC system, the power needed is taken from the batteries of the short range electrical aircraft. Based on the multidisciplinary optimization, the xHLFC system enables 45.5% drag reduction [12]. However, this comes with an additional penalty of mass of the battery needed for the aircraft.…”

Aerodynamic Efficiency Improvement on a NACA-8412 Airfoil via Active Flow Control Implementation

“…The Active Flow Control (AFC) technology applied to airfoils is beginning to be of common use, then a considerable number of recent papers tackle this matter [1][2][3]. Parametric analysis is still the most common methodology employed to evaluate the effect of the AFC on airfoils, yet the use of optimizers is becoming popular to obtain the most appropriate AFC parameters in any given application [4,5].…”