Wing Structural Changes of Hybrid-Electric Aircraft: a case of study

Resumo

Decarbonization and sustainability are emerging global goals as solutions to mitigate these temperature changes. The search for alternative fuels that reduce or eliminate gas emissions has become one of the most researched topics. In this context, electric energy has re-emerged as a source with the potential to revolutionize humanity, both for powering cars and airplanes. The attempt to use electric energy to power aircraft is not new. Pioneers tried to use it, but in the late nineteenth and early twentieth centuries, the weight-to-power ratio made this possibility unfeasible. Currently, with lighter engines and batteries with greater energy storage capacity, in addition to the use of renewable sources such as wind and photovoltaic energy, this possibility has begun to become a reality. Electric aircraft have begun to appear using photovoltaic panels on the wings and fuselage, demonstrating the viability of this energy alternative. Another option found was to electrify existing aircraft. This option does not simply involve removing the piston engine and turbine and replacing them with electric motors. From a structural perspective, the designer will have to deal with, at the very least, a fixed center of gravity (CG) instead of the CG movement during the flight that exists in aircraft as a result of the consumption of fuel. If he chooses to replace the propeller in the nose of the aircraft with several smaller propellers on the wings, called distributed propulsion, he will have to deal with changes in loads and moments, and it may be necessary to increase the number of ribs to increase their resistance. This work studies the transformation of an aircraft to hybrid-electric propulsion and the effects of these modifications on the wing structures and their attachment to the fuselage. The structural analysis is performed in a typical flight scenario at sea level, with a fixed standard atmosphere temperature, maximum cruise speed, and a specific angle of attack. It was necessary to determine a power-plant configuration to run a Vortex Lattice Method simulation to obtain the aerodynamic loads. Once the wing loads and the power plant were defined, it was possible to obtain the modified wing loads, and, in addition to the geometry model, it was possible to run the structural simulation. Despite the challenges related to added weight and reduced useful load, the developed study indicated that the proposed modification is viable from a structural viewpoint.