A New Aerodynamic Model for Unsteady Separated Flow on High Aspect Ratio Flexible Wings

  • Will J R Hewson

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)


Flow separation and dynamic stall have been an active research topic in the past decades. Traditionally, rotor blades have been at the forefront of research into dynamic stall. In recent years there has been an interest in high aspect ratio wings for commercial aircraft because of the potential for greater aerodynamic efficiency which has been necessitated by the requirement of greater fuel efficiency. However, future high aspect ratio wings will be more flexible to reduce mass, this in turn will lead to large deformations that can induce flow separation and stall.

Herein lies the motivation for this thesis, a tool is required that can rapidly give an engineering approximation to the response of a wing undergoing unsteady flow separation. The method developed in this thesis is capable of calculating the dynamic, aeroelastic response to an unswept, clean finite wing.

The proposed model is formulated through coupling the Beddoes-Leishman dynamic stall model with an unsteady lifting line theory for aerodynamic analysis of a finite wing undergoing unsteady motions. This is later extended to include a nonlinear beam model to produce an aeroelastic analysis tool. CFD (Computational Fluid dynamics) and experimental data is utilized to evaluate the model outputs for a finite wings undergoing pitching oscillations at high and low angles of attack. Overall the inclusion of a dynamic stall model offers significant improvement over uncorrected potential flow models.
Date of Award12 May 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorDorian P Jones (Supervisor) & Ann L Gaitonde (Supervisor)

Cite this