Three dimensionality and Instabilities of Leading-Edge Vortices

Lead Research Organisation: Imperial College London
Department Name: Dept of Aeronautics

Abstract

Aircraft is often subject to turbulence and gusts, which increase the aerodynamic forces and become a concern for the controllability of wings. Flow separation and formation of a "vortex" over the wing also occurs for unmanned air vehicles (UAVs) with flapping wings, wind turbines and rotating blades. The main aim of this project is to achieve a complete understanding of the initiation and growth of the three-dimensionality of the separated flow. The second aim is to develop flow/vortex control methods by means of excitation or delay of the initiation of instabilities. The proposed project will address these aspects through a combined experimental (University of Bath) and computational (Imperial College London) approach using state of the art facilities and methods. These include water tunnel experiments by using force, deformation and flow measurements as well as numerical simulations. Expected outcomes include better understanding of the flow separation and vortices shed from the wings in unsteady flows and developing novel flow control methods which could be used for alleviation of extreme loads on wings. This could have main impact on the design of lighter aircraft, UAVs and wind turbines as well as help with improved safety.

Publications

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Onur Sun (2022) Leading-Edge Vortex Dynamics on Plunging Airfoils and Wings in Journal of Fluid Mechanics

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Son O (2022) Leading-edge vortex dynamics on plunging airfoils and wings in Journal of Fluid Mechanics

 
Description We have identified and modelled how the vortex which is created on the leading edge of a wing undergoing plunging motion is generated and evolves around the wing tip region. This greater understanding of the flow dynamics helps build our knowledge about improving the ability to generate and control lift and drag on smaller flapping aircraft and birds.
Exploitation Route The greater understanding of dynamics stall can help designers of smaller drones and even in larger aircraft as they approach larger angle of attacks where stall can arise. Leading edge vortices of this nature also arise in rotating problems such as wind turbines.
Sectors Aerospace, Defence and Marine

 
Description We have discussed the results with our industrial collaborators at McLaren Racing who are interested in adopting the software.
First Year Of Impact 2001
Sector Transport
 
Description McLaren Racing 
Organisation McLaren Racing
Country United Kingdom 
Sector Private 
PI Contribution We have transferred fundamental ideas behind vortex stability and identification to their design practice. More recently we are been applying computational modelling tools developed in an academic setting to example flow problems of direct interest to McLaren.
Collaborator Contribution Data and motivation on how to focus our research direction
Impact .
Start Year 2007
 
Title Nektar++ v5.0.1 
Description A tensor product based finite element package designed to allow one to construct efficient classical low polynomial order h-type solvers (where h is the size of the finite element) as well as higher p-order piecewise polynomial order solvers. 
Type Of Technology Software 
Year Produced 2021 
Open Source License? Yes  
Impact The latest version of Nektar++, v5.0.1, was released on the 21st January 2021. It can be downloaded from the downloads page. 
 
Description "Numerical simulation and experiment of the three-dimensional leading-edge vortex generated by a plunging wing" at The 13th International ERCOFTAC symposium on Engineering, Turbulence, Modelling and Measurements (ETMM13). 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Gao, A. K., Cantwell, C. D., Sherwin, S. J., Son, O., Wang, Z., & Gursul, I. (2021, September). Numerical simulation and experiment of the three-dimensional leading-edge vortex generated by a plunging wing. In The 13th International ERCOFTAC symposium on Engineering, Turbulence, Modelling and Measurements (ETMM13).
Year(s) Of Engagement Activity 2021
URL https://etmm.ercoftac.org/etmm/past-etmm-conference/etmm-13-in-rhodes-20/
 
Description Three-dimensional instabilities of vortices shed from a plunging wing: Computations. In APS Division of Fluid Dynamics Meeting (2020) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Gao, A. K., Sherwin, S. J., & Cantwell, C. D. (2020). Three-dimensional instabilities of vortices shed from a plunging wing: Computations. In APS Division of Fluid Dynamics Meeting Abstracts (pp. P19-005).
Year(s) Of Engagement Activity 2020