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Low Reynolds number performance of a model scale t-foil
journal contribution
posted on 2023-05-18, 12:26 authored by Javad MehrJavad Mehr, Michael DavisMichael Davis, Jason Ali-LavroffJason Ali-LavroffSubmerged T-foils are an essential forward component of the ride control systems of high speed ferries. A model scale T-Foil for a 2.5m towing tank model of a 112m INCAT Tasmania high-speed wave-piercer catamaran has been tested for both static and dynamic lift performance. The tests were carried out using a closed-circuit water tunnel to investigate the lift and drag characteristics as well as frequency response of the T-Foil. The model T-Foil operates at a Reynolds number of approximately I05 , has an aspect ratio of 3.6 and a plan form which is strongly tapered from the inboard to outboard end. All of these factors, as well as strut and pivot interference, influence the steady lift curve slope (deL) of the da model T-foil which was found to be 61% of the value for an ideal aerofoil with elliptic loading. The T-foil dynamic performance was limited primarily by the stepper motor drive system and connection linkage. At the frequency of maximum motion of the 2.5 m catamaran model (about 1.5Hz) the model T-foil has approximately 5% reduction of amplitude and 15 degrees of phase shift relative to the low frequency response. Only very small limitations arose due to the unsteady lift as predicted by the analysis of Theodorsen. It was concluded that the model scale T-foil performed adequately for application to simulation of a ride control system at model scale.
History
Publication title
International Journal of Maritime EngineeringVolume
157Issue
Part A3Pagination
A175-A187ISSN
1479-8751Department/School
School of EngineeringPublisher
Royal Institution of Naval ArchitectsPlace of publication
United KingdomRights statement
Copyright 2015 Royal Institution of Naval ArchitectsRepository Status
- Restricted