Unsteady Lift of an Oscillating Wing below Free-Surface
| Project/Area Number |
01550354
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
船舶抵抗・運動性能・計画
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| Research Institution | Kyushu University |
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Principal Investigator |
KYOZUKA Yusaku Grad. Sch. Sci. Eng. Professor Kyushu Univ., 大学院総合理工学研究科, 教授 (80177948)
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| Co-Investigator(Kenkyū-buntansha) |
HORI Tutomu Res. Inst. Appl. Mech. Res. Assoc. Kyushu Univ., 応用力学研究所, 助手 (10199523)
NAKAMURA Masahiko Res. Inst. Appl. Mech. Res. Assoc. Kyushu Univ., 応用力学研究所, 助手 (40155859)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Oscillating Wing / Hydrofoil / Unsteady Lift / Free-Surface Flow / 揚力面理論 |
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| Research Abstract |
A new numerical method has been developed to analyze unsteady hydrodynamic forces of 3D lifting surface of arbitrary plan form in infinite flow, in which velocity potential is expressed by the doublet distribution over wing and the wake. The results by this method show good agreement with existing theories and experiments for some rectangular and triangular wings in steady and unsteady problems.
For 2D wings below free-surface, an integral equation method which includes the free-surface effects and the thickness of the wing exactly is developed. Following conclusions are obtained from numerical calculations and experiments.
1) There is non-zero attack angles where the lift of the wing becomes zero.
2) Thickness of the wing section does not affect hydrodynamic forces so much that thin wing would give good approximation.
3) Free-surface effects on hydrodynamic forces appear at the ratio of the oscillating frequency to the uniform flow velocity takes some values.
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Report
(3 results)
Research Products
(11 results)
