# A Conceptual Design Methodology for e-VTOL Aircraft for Urban Air Mobility
###### Abstract
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Reference** & \
\begin{tabular}{c} **N. of** \\ **Passengers** \\ \end{tabular} & **VTOL Type** & **Aerodynamic Model** & **Weight Model** & **Optimization** &
\begin{tabular}{c} **Noise** \\ **Evaluation** \\ \end{tabular} \\ \hline
[39] & 10 & Full-electric T-W & \
\begin{tabular}{c} Semi-empirical \\ formulation [49] \\ \end{tabular} &
\begin{tabular}{c} Take-off Weight \\ Build-up \\ method [49] \\ \end{tabular} & Yes & No \\ \hline
[40] & 2 & Full-electric T-R & VLM and CFD &
\begin{tabular}{c} Semi-empirical \\ formulation not \\ stated \\ \end{tabular} & Yes & No \\ \hline
[41] & 2–10 & Full-electric H & \
\begin{tabular}{c} Semi-empirical \\ formulation [50] \\ \end{tabular} &
\begin{tabular}{c} Component \\ weight build-up \\ method [50] \\ \end{tabular} & No & No \\ \hline
[42] & 2–10 & \begin{tabular}{c} Full-electric H, \\ M-R, T-R and L + C \\ \end{tabular} & \
\begin{tabular}{c} Semi-empirical \\ formulation [49; 51] \\ \end{tabular} &
\begin{tabular}{c} Take-off Weight \\ Build-up \\ method [52; 53] \\ \end{tabular} & No & No \\ \hline
[43] & 4 & Full-electric L + C & \
\begin{tabular}{c} Semi-empirical \\ formulation [54] \\ \end{tabular} &
\begin{tabular}{c} Take-off Weight \\ Build-up \\ method [52] \\ \end{tabular} & No & No \\ \hline
[44] & 3 & \begin{tabular}{c} Full-electric H, T-W, \\ T-R and L + C \\ \end{tabular} & \
\begin{tabular}{c} No computed, \\ assumption on \\ aerodynamic efficiency \\ \end{tabular} &
\begin{tabular}{c} Take-off Weight \\ Build-up \\ method [49] \\ \end{tabular} & Yes & Yes \\ \hline
[45] & 2/6 & \
\begin{tabular}{c} Hybrid-electric \\ T-W \\ \end{tabular} & CFD &
\begin{tabular}{c} Take-off Weight \\ Build-up \\ method [49] \\ \end{tabular} & No & No \\ \hline
[46] & 3 & \
\begin{tabular}{c} Hybrid-electric \\ tube-and-wing \\ \end{tabular} & JVL [46] &
\begin{tabular}{c} Component \\ weight build-up \\ method \\ \end{tabular} & Yes & No \\ \hline
[47] & 1/6/15 & \begin{tabular}{c} Hybrid-electric \\ M-R, H and T-W \\ \end{tabular} & \
\begin{tabular}{c} Semi-empirical \\ formulation \\ \end{tabular} &
\begin{tabular}{c} Detailed mass \\ breakdown \\ \end{tabular} & Yes & No \\ \hline
[48] & 6 & \begin{tabular}{c} Hybrid-electric and \\ full-electric M-R, H \\ and L + C \\ \end{tabular} & \
\begin{tabular}{c} Semi-empirical \\ formulation \\ \end{tabular} &
\begin{tabular}{c} Detailed mass \\ breakdown \\ \end{tabular} & Yes & No \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Main information of the conceptual design methodologies described in (39–48). In the first part of this paper, a new conceptual design methodology for the air taxi aircraft category is presented; the proposed methodology exploits physics-based models to achieve accurate results as much as possible. In the aerodynamic model, a VLM method combined with the component build-up method [49], has been implemented in order to estimate the polar drag of conventional and disruptive architectures (e.g., box-wing [55]). Weight estimation has been obtained by a detailed component weight build-up method modified ad-hoc to evaluate the mass of the components of the electrical powertrains. Moreover, aircraft flight performance has been computed by the Euler integration method, ensuring accurate energy consumption evaluation for each phase of the mission. The results of the design procedure are then compared with the outcomes available from the reference literature. Then, the methodology described here is applied to the design of an innovative air vehicle based on box-wing configuration [55,56] called _TiltOne_. Several configurations have been evaluated, and results from sensitivity analyses to main design parameters, such as propellers' disk loading and wing loading, and TLARs parameters (speed, range and technological level of electrical system) are widely analysed. Finally, limitations and potential benefits of this urban air vehicle are discussed, together with the analysis of possible operating scenarios.