Midterm Report - Multi-Disciplinary Design and Optimisation of a Long-Range eVTOL Aircraft

In aircraft structural design it is of utmost importance to minimise the structural mass while maintaining a durable structure that is able to sustain the design loads for a predetermined number of flight cycles. The present manuscript investigates a methodology for the preliminary design and analysis of a tandem-wing long-range electric vertical takeoff and landing (eVTOL) aircraft. First, a class I weight estimation for initial loads calculation is presented. Next, the flight envelope, main load cases and failure modes considered in this preliminary design are explained. Load approximations for the wing structures in cruise and take-off conditions are presented and discussed. Next, Cessna's class II semi-empirical weight estimation method is applied to calculate the mass of 11 eVTOL aircraft subsystems. A design concept for the wing tilting mechanism is proposed. Thereafter, an initial fuselage layout design is presented, followed by a discussion on design for crashworthiness. The aeroelastic behaviour of the wing and the whirl flutter considering the propeller engine structures is investigated. Lastly, refinements in the design parameterization are implemented concerning the thickness distributions in the structural elements of the wingbox, and finally a sizing of the wing rotating shaft is performed.

Section: Load Cases and Failure Modesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Preliminary design and analysis of crashworthy structures for a long-range eVTOL aircraft

Wadia

Buszek

Poliakov

et al. 2022

“…A sensitivity study of the neutral point and controllability limit found that 𝑆 𝑟 𝑒𝑎𝑟 /𝑆 𝑓 𝑤𝑑 and 𝐴𝑅 𝑓 𝑤𝑑 are the most powerful parameters to affect the stability and controllability limits of the aircraft (see [1,2,9]). The relative wing size strongly affects both stability and controllability, while the front wing aspect ratio mainly impacts stability.…”

Section: B Relative Wing Sizing and Placementmentioning

confidence: 99%

“…It is noted that a certain increase in 𝐶 𝐿 𝑓 𝑤𝑑 and a decrease in 𝐶 𝐿 𝑟𝑒𝑎𝑟 are needed in order to obtain a feasible CG range (see [9]). This ensures not only that the aircraft can be trimmed at stall, but also that the elevators can be utilised to control the aircraft in all other horizontal flight conditions.…”

Section: Elevator Sizingmentioning

confidence: 99%

Preliminary control and stability analysis of a long-range eVTOL aircraft

Schoser

Cuadrat-Grzybowski

Castro

2022

This study proposes a strategy to incorporate control and stability aspects into the preliminary design of a tandem-wing, long-range eVTOL aircraft concept. Four operational phases are considered: cruise, transition, hover, and ground operation. For cruise, a method to design for open-loop stability and size aerodynamic control surfaces is presented. Furthermore, a controller is designed to improve handling qualities. For hover controllability by differential thrust is considered, and for ground operation, the positioning of the landing gear is performed according to clearance and tip-over requirements. A novel analytical model is derived for the tandem wing aircraft in order to estimate during the preliminary design phase the stability derivatives of the aerodynamic forces and moments. The transition manoeuvre between vertical and horizontal flight is only treated with qualitative considerations, due to the highly nonlinear dynamics involved during this flight phase.

“…If the weight would not increase, the aircraft would have a range of 400 km. For more information on the Wigeon, please refer to [2], [3] and [1]. Apart from the energy consumption, it is also important to estimate the performance of the aircraft.…”

Section: Introductionmentioning

confidence: 99%

Preliminary performance assessment of a long-range eVTOL aircraft

Beyne

Castro

2022

The electric aircraft industry is starting to gain traction mainly due to the growing specific energy capacity of new batteries. Within this industry electric vertical takeoff and landing (eV-TOL) aircraft serve the urban and regional air mobility market, requiring less infrastructure investments such as large airports, due to their vertical takeoff and landing capabilities. The present study investigates the preliminary performance evaluation of a tandem wing long-rage eVTOL concept. First, the power and energy consumption of a typical mission with a range of 300 km is estimated, consisting of: vertical takeoff, climb, cruise, loiter, descent, and vertical landing. The takeoff, climb, descend and landing phases are simulated numerically. The climb performance is evaluated in vertical and horizontal configuration. The flight paths were optimized aiming at a minimum energy consumption, showing very high climb rates due to the large power needed for vertical takeoff. To quantify the effect of different payloads on the aircraft range, a payload range diagram is constructed. Next, a sensitivity analysis is performed with respect to some operational parameters, relating the range and mission block speed to cruising altitude, cruise speed and wind speed. Finding the sensitivity of the flight range to these input parameters allows one to adequately select the safety margins for a given battery capacity. Finally, a conclusion and recommendation for next studies is given.