Design and sizing eVTOL aircraft (aerodynamics portion)

• Main Author: Dikshit, Abhijnan
• Other Authors: James Wang Ming
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Aeronautical engineering::Aircraft; Engineering::Aeronautical engineering::Aerodynamics
• Online Access: https://hdl.handle.net/10356/158673
• Institution: Nanyang Technological University

The cruise range of eVTOL aircraft has been improved with the addition of wing surfaces so that the aircraft can take off vertically like a helicopter but achieve good cruise efficiency like an aircraft. The addition of wings to eVTOL aircraft has led to the exploration of many different wing configurations, each with its own pros and cons. Out of these configurations, the tandem wing aircraft configuration is the least studied configuration, and it is becoming increasingly popular in the design of eVTOL aircraft. As such, this report focuses on expanding the knowledge of wing design of a tandem wing eVTOL aircraft. This is done through a basic comparison of the aerodynamic efficiency and flight stability of a tandem wing aircraft with other aircraft configurations and by performing a parametric and optimization study on a generic tandem wing aircraft design. A lower order vortex lattice model coupled with a mass estimation model is used to perform all the aerodynamics and stability calculations. An open-source multidisciplinary optimization framework is used to perform the optimization study of wing geometry. The results of the aircraft comparison study show that a flying wing aircraft configuration has the highest aerodynamic efficiency whereas a tandem wing aircraft with wings of the same aspect ratio has the lowest aerodynamic efficiency. On the other hand, the tandem wing aircraft configuration offers good longitudinal stability characteristics. A conventional wing-tail aircraft offers a good compromise of stability and aerodynamics. The results of the parametric and optimization study show that relative wing sizes and wingspan greatly affect the aerodynamics of a tandem wing aircraft. The relative wing sizes also affect the longitudinal and directional stability of a tandem wing aircraft. Wing sweep and wing dihedral have a significant effect on the lateral stability of a tandem wing aircraft. The results presented in this report have also been related back to the practical design of VTOL and eVTOL aircraft.