1998 Fiscal Year Final Research Report Summary
Development of Flexible Sail to Improve Thrust Performance by Using Oscillation of Sailing Vessel
| Project/Area Number |
09651018
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
船舶工学
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| Research Institution | Kanazawa Institute of Technology |
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Principal Investigator |
MASUYAMA Yutaka Kanazawa Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (10101362)
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| Co-Investigator(Kenkyū-buntansha) |
FUKASAWA Toichi Kanazawa Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (80143171)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Sailing Vessel / Sailing Yacht / Fluid Dynamic Force on Sail / Lifting Surface Theory / Boat Oscillation / Sail Dynamometer / Full Scale Boat Test / Numerical Simulation |
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| Research Abstract |
This research aims to investigate an increasing mechanism of sail thrust using distortion of the flexible sail caused by oscillation of a sailing vessel such as pitching or rolling. First, numerical calculations were performed to estimate the variation of sail forces by pitching or rolling motion. The vortex lattice method was adopted as the numerical calculation method, where shedding vortex filaments proceeded downstream in each time. The calculated results showed that the pitching motion and in particular rolling motion improved thrust of sail. On the other hand, sail forces under various kinds of boat motion were measured in a full-scale sailing boat with the use of a sail force dynamometer, which consisted of an aluminum frame fixed to the hull by way of several load cells. The calculated results were compared with the measured and the accuracy of calculation method was confirmed.
Then, a sail distortion system was constructed to generate almost same distorted shape due to the boat oscillation. This system consisted of two electric actuators, which were set on the platform of the dynamometer frame. The actuators fed in and out the sail control sheets or mast-bend control wires, and distorted the sail shape continuously in particular twist angle. This system showed that the variation range of sail force caused by the continuous distortion was larger than the case of static change.From this research, it can be considered that the investigate system of an increasing mechanism of sail thrust due to the boat oscillation has been established. The numerical calculations for the continuous distortion of the sail are still continuing, and the calculated results have been compared with the measured.
From these results, the required characteristics for the flexible sail to improve thrust performance will become clear in detail.
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