Coupled unsteady actuator disc and linear theory of an oscillating foil propulsor
Coupled unsteady actuator disc and linear theory of an oscillating foil propulsor
Linear unsteady aerofoil theory, while successfully used for the prediction of unsteady aerofoil lift for many decades, has yet to be proven adequate for predicting the propulsive performance of oscillating aerofoils. In this paper we test the hypothesis that the central shortcoming of linear small-amplitude models, such as the Garrick function, is the failure to account for the flow acceleration caused by aerofoil thrust. A new analytical model is developed by coupling the Garrick function to a cycle-averaged actuator disc model, in a manner analogous to the blade-element momentum theory for wind turbines and propellers. This amounts to assuming the Garrick function to be locally valid and, in combination with a global control volume analysis, enables the prediction of flow acceleration at the aerofoil. The new model is demonstrated to substantially improve the agreement with Large-Eddy Simulations of an aerofoil in combined heave and pitch motion.
CFD, Numerical modeling, flapping foils
Smyth, Amanda S.M.
22ae3039-4683-4869-83fb-5d7f09ee95b5
Nishino, Takafumi
34d25fde-acbb-4cac-8491-bcc97d4e6994
Zurman-Nasution, Andhini
b9e5a90e-08c3-4922-8307-26c420e854d8
Smyth, Amanda S.M.
22ae3039-4683-4869-83fb-5d7f09ee95b5
Nishino, Takafumi
34d25fde-acbb-4cac-8491-bcc97d4e6994
Zurman-Nasution, Andhini
b9e5a90e-08c3-4922-8307-26c420e854d8
Smyth, Amanda S.M., Nishino, Takafumi and Zurman-Nasution, Andhini
(2024)
Coupled unsteady actuator disc and linear theory of an oscillating foil propulsor.
Journal of Fluid Mechanics, 995, [R1].
(doi:10.1017/jfm.2024.624).
Abstract
Linear unsteady aerofoil theory, while successfully used for the prediction of unsteady aerofoil lift for many decades, has yet to be proven adequate for predicting the propulsive performance of oscillating aerofoils. In this paper we test the hypothesis that the central shortcoming of linear small-amplitude models, such as the Garrick function, is the failure to account for the flow acceleration caused by aerofoil thrust. A new analytical model is developed by coupling the Garrick function to a cycle-averaged actuator disc model, in a manner analogous to the blade-element momentum theory for wind turbines and propellers. This amounts to assuming the Garrick function to be locally valid and, in combination with a global control volume analysis, enables the prediction of flow acceleration at the aerofoil. The new model is demonstrated to substantially improve the agreement with Large-Eddy Simulations of an aerofoil in combined heave and pitch motion.
Text
JFMrapids2024_SmythNishinoZurmanNasution_Final
- Accepted Manuscript
Text
coupled-unsteady-actuator-disc-and-linear-theory-of-an-oscillating-foil-propulsor
- Version of Record
More information
Accepted/In Press date: 19 June 2024
e-pub ahead of print date: 18 September 2024
Keywords:
CFD, Numerical modeling, flapping foils
Identifiers
Local EPrints ID: 492517
URI: http://eprints.soton.ac.uk/id/eprint/492517
ISSN: 0022-1120
PURE UUID: c1282a38-67a8-49de-947b-5ea59dbeb3b6
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Date deposited: 30 Jul 2024 16:39
Last modified: 16 Oct 2024 02:06
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Contributors
Author:
Amanda S.M. Smyth
Author:
Takafumi Nishino
Author:
Andhini Zurman-Nasution
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