Development of unsteady three-dimensional lifting line model and its application in aeroelasticity

• Main Author: Chow, Earl Jun Zhong
• Other Authors: Basman Elhadidi
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Aeronautical engineering::Aerodynamics
• Online Access: https://hdl.handle.net/10356/141883
• Institution: Nanyang Technological University

Most fixed wing aircraft face a dangerous consequence of speed: aeroelasticity. Aeroelastic vibration can lead to a loss in lift, an increase in drag and very rarely, catastrophic failure. As such, determining the aeroelastic characteristics of a wing is key to reduce the risk of structural failure. By modifying certain key aspects of Prandtl’s Lifting Line model, this study presents an unsteady three-dimensional aerodynamic model and its application in aeroelasticity. This report explains how the mathematical model is developed, the theories that it is grounded upon, and the results of the MATLAB simulations of the model. This mathematical method shows good agreement when compared with Theodorsen’s unsteady aerodynamics. It is also able to exhibit quick changes of aerodynamic lift due to a heaving or bending wing. By coupling this aerodynamic model with a lumped mass model, the aeroelastic system is able to show the vibrational characteristics of a straight wing due to a three-dimensional lift distribution. However, there are several limitations to this study. Structural torsional twist is neglected in the calculations, and the model is only applicable to straight wings. Nonetheless, future work could be done on this study to expound its limitations and downfalls.