Study on Influence of Configuration of Bulges on Stall Characteristics of Two-Element Wingsails for Ships

The tubercles on the flipper of humpback whales are beneficial for improving their locomotion performance. Based on biomimetic design, the bulge model was developed to mimic this function through cubic B-spline curve fitting, aiming to improve the stall performance of the two-element wingsail. The n...

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Bibliographic Details
Main Authors: Chen Li, Binxin Wu, Huabing Wen, Junfu Yuan
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Journal of Marine Science and Engineering
Subjects:
Online Access:https://www.mdpi.com/2077-1312/13/2/337
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Summary:The tubercles on the flipper of humpback whales are beneficial for improving their locomotion performance. Based on biomimetic design, the bulge model was developed to mimic this function through cubic B-spline curve fitting, aiming to improve the stall performance of the two-element wingsail. The numerical calculation method was validated against experiments to ensure the reliability of the numerical results. Five models of the bulges of the main wing were developed, and the influence of different bulges on the stall performance of the two-element wingsail under logarithmic gradient wind conditions was examined. By analyzing its lift and drag characteristics, pressure load distribution, and flow field near the stall angle, the mechanism by which the bulges improved the stall characteristics of the two-element wingsail was revealed. The result indicated that the two-element wingsail in the Case 5 scheme has a maximum lift coefficient of 1.25, and that the lift reduction in the early stage of stall is only 8.8%, which is 43.6% less than the original wingsail lift reduction. As the bulge size increases the strength of the forward vortex created by the middle larger bulge increases, resulting in the absence of a symmetrical vortex structure on the suction surface of the wingsail, causing high fluid momentum band deflection. The energy of the boundary layer is supplemented by vorticity transport, promoting the formation of attached flow on the side of the smaller bulge and improving the lift coefficient.
ISSN:2077-1312