What is it about?
Electric vertical takeoff and landing (eVTOL) aircraft are being developed worldwide, with different designs. Many companies are investing a lot, and researchers are interested in making transportation more efficient and eco-friendly. Our study focuses on designing eVTOLs in the early stages and evaluating their efficiency during a typical mission. We want these aircraft to be not only innovative but also efficient for urban air travel. We use FLOWUnsteady, an open-source tool, to study how aerodynamic forces affect the aircraft during a regular mission. Our goal is to find the best eVTOL design by analyzing its energy efficiency, especially concerning battery size. We aim to balance having a lightweight battery with ensuring the eVTOL works efficiently. We adjust the wing design to make the most of wing span and low tapper ratio.
Featured Image
Photo by Karl Greif on Unsplash
Why is it important?
With the global interest and substantial investments in eVTOLs, our research delves into the specific challenges related to battery sizing for optimal performance. This aspect is crucial for the success of urban air mobility and sustainable aviation solutions. By leveraging FLOWUnsteady and the reformulated vortex particle method, we provide a detailed analysis of aerodynamic forces on various eVTOL structures during regular missions. Our focus on achieving a balance between minimum battery weight and efficiency sets our work apart. This research not only contributes insights for future studies but also empowers engineering decision-making by offering a comprehensive sizing model. In a rapidly evolving field, our timely investigation aims to pave the way for advancements in eVTOL design, making our work essential for researchers, engineers, and industry professionals interested in the practical and efficient implementation of these innovative aircraft.
Perspectives
As a researcher involved in this study, I am personally enthusiastic about the potential impact of our work on the future of electric vertical takeoff and landing (eVTOL) aircraft. The growing interest and investment in this technology underscore its significance in addressing urban air mobility challenges and contributing to sustainable aviation. Our focus on the nuanced aspects of battery sizing for optimal efficiency reflects a commitment to overcoming crucial hurdles in the practical implementation of eVTOLs. The use of FLOWUnsteady and the reformulated vortex particle method adds a robust analytical dimension to our research, enhancing its reliability and relevance.
Gabriel Souza
Universidade Federal de Uberlandia
Read the Original
This page is a summary of: Design optimization and mission efficiency analysis of an eVTOL, January 2024, American Institute of Aeronautics and Astronautics (AIAA),
DOI: 10.2514/6.2024-1086.
You can read the full text:
Resources
An Efficient and Robust Sizing Method for eVTOL Aircraft Configurations in Conceptual Design
This paper presents the development of a robust sizing method to efficiently estimate and compare key performance parameters in the conceptual design stage for the two main classes of fully electric vertical take-off and landing (eVTOL) aircraft, the powered lift and wingless aircraft types. The paper investigates hybrids of classical root-finding methods: the bisection, fixed-point and Newton-Rapson methods for use in eVTOL aircraft sizing. The improved convergence efficiency of the hybrid methods is at least 70% faster than the standard methods. This improved efficiency is significant for complex sizing problems. The developed sizing method is used to investigate the comparative performance of the wingless and powered lift eVTOL aircraft types for varying mission lengths. For a generic air taxi mission with a payload of 400 kg, the powered lift type demonstrates its mass efficiency when sized for missions above 10 km in range. However, the simpler architecture of the wingless eVTOL aircraft type makes it preferable for missions below 10 km in range when considering energy efficiency. The results of the sizing study were compared against a selection of eVTOL aircraft data. The results showed a good agreement between the estimated aircraft mass using the proposed sizing method and published eVTOL aircraft data.
FLOWUnsteady: An Interactional Aerodynamics Solver for Multirotor Aircraft and Wind Energy
The ability to accurately and rapidly assess unsteady interactional aerodynamics is a shortcoming and bottleneck in the design of various next-generation aerospace systems: from electric vertical takeoff and landing (eVTOL) aircraft to airborne wind energy (AWE) and wind farms. In this study, we present a meshless CFD framework based on the reformulated vortex particle method (rVPM) for the analysis of complex interactional aerodynamics. The rVPM is a large eddy simulation (LES) solving the Navier-Stokes equations in their vorticity form. It uses a meshless Lagrangian scheme, which not only avoids the hurdles of mesh generation, but it also conserves the vortical structure of wakes over long distances with minimal numerical dissipation, while being 100x faster than conventional mesh-based LES. Wings and rotating blades are introduced in the computational domain through actuator line and actuator surface models. Simulations are coupled with an aeroacoustics solver to predict tonal and broadband noise radiated by rotors. The framework, called FLOWUnsteady, is hereby released as an open-source code and extensively validated. Validation studies published in previous work by the authors are summarized, showcasing rotors across operating conditions with a rotor in hover, propellers, a wind turbine, and two side-by-side rotors in hover. Validation of rotor-wing interactions is presented simulating a tailplane with tip-mounted propellers and a blown wing with propellers mounted mid-span. The capabilities of the framework are showcased through the simulation of a tiltwing eVTOL vehicle and an AWE wind-harvesting aircraft, featuring rotors with variable RPM, variable pitch, tilting of wings and rotors, non-trivial flight paths, and complex aerodynamic interactions.
Contributors
The following have contributed to this page
