Future pathways for eVTOLs: A design optimization perspective

TL;DR

The paper introduces a multidisciplinary design optimization framework for conceptual eVTOL design that integrates economic viability, environmental impact, and regulatory considerations. A cross-transportation Figure of Merit (FoM) enables comparing eVTOL variants against ground and air modalities, with four objective-specific designs analyzed: profit-maximized, TOC-minimized, GWP-minimized, and FoM-maximized. A gradient-based optimizer with a 70 km sizing mission couples mass, aerodynamics, power/energy, acoustics, and lifecycle emissions to reveal trade-offs among profitability, flexibility, and sustainability. The results show distinct design compromises, underscoring the importance of multi-disciplinary co-design and stakeholder-driven objectives in guiding urban air mobility adoption and policy. The framework offers a generalizable platform for evaluating eVTOL deployments within broader transportation systems and highlights pathways for battery, charging, and infrastructure innovations to improve sustainability and economics.

Abstract

The rapid development of advanced urban air mobility, particularly electric vertical take-off and landing (eVTOL) aircraft, requires interdisciplinary approaches involving the future urban air mobility ecosystem. Operational cost efficiency, regulatory aspects, sustainability, and environmental compatibility should be incorporated directly into the conceptual design of aircraft and across operational and regulatory strategies. In this work, we apply a novel multidisciplinary design optimization framework for the conceptual design of eVTOL aircraft. The framework optimizes conventional design elements of eVTOL aircraft over a generic mission and integrates a comprehensive operational cost model to directly capture economic incentives of the designed system through profit modeling for operators. We introduce a novel metric, the cross-transportation Figure of Merit (FoM), to compare the optimized eVTOL system with various competing road, rail, and air transportation modes in terms of sustainability, cost, and travel time. We investigate four objective-specific eVTOL optimization designs in a broad scenario space, mapping regulatory, technical, and operational constraints to generate a representation of potential urban air mobility stakeholder-centric design objectives. The analysis of an optimized profit-maximizing eVTOL, cost-minimizing eVTOL, sustainability-maximizing eVTOL, and a combined FoM-maximizing eVTOL design highlights significant trade-offs in the area of profitability, operational flexibility, and sustainability strategies. This underlines the importance of incorporating multiple operationally tangential disciplines into the design process, while also reflecting the diverse priorities of stakeholders such as operators, regulators, and society.

Figures (8)

• Figure 1: Framework for the conceptual eVTOL design optimization, illustrating the key geometric parameters, the mission profile, and the operational constraints. It outlines the four primary optimization objectives: maximum profit, minimum total operating cost (TOC), minimum Global Warming Potential (GWP), and maximum stakeholder-centric Figure of Merit (FoM), which are compared against conventional transportation modes (illustration adapted from nasa_uam_refsAIP_SkyVector).
• Figure 2: Extended Design Structure Matrix for single-objective optimization: $FoM_{evtol}$, yellow line; Total Operating Cost $\mathcal{C}_{\text{TOC}}$, red line; Operating Profit $\Pi_{\text{ops}}$, black line; Operational Global Warming Potential $GWP_{ops}$, light brown.
• Figure 3: Sizing mission: (a) profile and (b) segments.
• Figure 4: Optimization results of profit-maximizing conceptual eVTOL design: aircraft design, battery behavior, operating window usage, global warming potential, operating costs and cross-transportation comparison.
• Figure 5: Optimization results of TOC-minimizing conceptual eVTOL design: aircraft design, battery behavior, operating window usage, global warming potential, operating costs and cross-transportation comparison.