碩士 / 國立臺灣海洋大學 / 系統工程暨造船學系 / 107 / The objective of this paper is to predict the dipole noise caused by the underwater propeller for a surface vessel, and compare the calculated results with experimental data to verify the used method. Propeller cavitation is not allowed when the submarines dive at diving depth and the surface vessels operate at cruising speed. For these cavitation-free propellers operating in the non-uniform wake, the dominate noises are generated by the unsteady forces (i.e. dipole noise). The unsteady forces include three components: the axial thrust, the tangential torque, and the radial force; but the radial force is generally omitted, because it is much smaller than the others. The unsteady forces are the dipole sources, and would cause the blade-rate frequency noise. The unsteady forces are calculated by computational fluid dynamics(CFD), and transformed into the dipole strengths. Then, the dipole strengths are applied in the liner wave theory for solving the noises. The predicted noises will compare with the experiment data measured in the underwater anechoic chamber of NTOU Large Cavitation Tunnel to verify the numerical scheme. There are few literatures discussing the propeller dipole noise, and the measurements are always classified. Thus, this paper will be referable for further associated researches.
In this paper, a surface vessel with the non-cavitating propeller is taken as the computing sample. The measured data are corrected by excluding the low-frequency reverberating amplitudes. The difference between numerical and measured results is acceptable. The comparisons show that the present numerical scheme is practical to predict the propeller dipole noise.
| Identifer | oai:union.ndltd.org:TW/107NTOU5345006 |
| Date | January 2019 |
| Creators | Lin, Yan-Jhang, 林彥璋 |
| Contributors | Kao, Jui-Hsiang, 高瑞祥 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 47 |
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