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Noriyuki Sasaki Mitsunori Murakami Kazuo Nozawa Shunji Soejima Akira Shiraki Takeshi Aono Tomeo Fujimoto Isao Funeno Norio Ishii Hiroshi Onogi 《Journal of Marine Science and Technology》1998,3(1):3-21
A new type of contrarotating propeller (CRP) system has been developed through the cooperative research work of five shipbuilding companies in Japan (Hitachi Zosen Corporation; Kawasaki Heavy Industries, Ltd.; Mitsui Engineering and Shipbuilding Co., Ltd.; NKK Corporation; and Sumitomo Heavy Industries, Ltd.). This paper describes a design system for an optimum CRP, which is one of the numerous outcomes of this work. The optimum design system is composed of three theoretical programs: (1) the design program of the optimum CRP; (2) the steady lifting surface program of the CRP; (3) the unsteady lifting surface program of the CRP. These theoretical programs will be discussed in the first part of the paper, and the design system supported by these theoretical programs will then be verified by comparing calculated and experimental results.Translation of an article that appeared in the Journal of The Society of Naval Architects of Japan, vol. 180 (1996): The original article won the SNAJ prize, which is awarded annually to the best papers selected from the SNAJ Journal, JMST, or other quality journals in the field of naval architecture and ocean engineering. 相似文献
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Takeshi Kinoshita Weiguang Bao Shunji Sunahara 《Journal of Marine Science and Technology》1997,2(3):135-147
The problem of the interaction of multiple cylinders oscillating in waves and slow current is considered. The interaction
is represented by waves emitted from adjacent cylinders towards the cylinder under consideration. Wave drift forces and moment
in the horizontal plane are calculated by the far-field method based on the conservation of momentum or angular momentum.
A semianalytical formula for the calculation of the wave drift damping is then deduced. The conservation of the integrals
in these formulae is proved. Special treatments to improve the accuracy of results are discussed. Comparisons between calculated
results and experimental measurements are made, showing satisfactory agreement. Effects of various combinations of current
direction and incident wave angle on the wave drift damping and damping moment are also examined. 相似文献
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Akihisa Konno Kazuaki Wakabayashi Hajime Yamaguchi Masatsugu Maeda Norio Ishii Shunji Soejima Koyu Kimura 《Journal of Marine Science and Technology》2002,6(4):181-192
The bursting phenomenon of tip vortex cavitation of a propeller sometimes causes severe high-frequency vibration, but its
mechanism has not yet been elucidated. In this study, we carried out model experiments by changing the propellers, wake distributions,
thrust coefficients, and cavitation numbers parametrically, examined the bursting phenomenon with a high-speed video camera,
and measured the pressure fluctuations caused by the phenomenon. We also measured flow distribution around the tip vortex.
As a result, we found that in the bursting phenomenon, large pressure fluctuations occurred twice, and that they strongly
depended on the wake distribution. Two means were suggested to suppress the bursting phenomenon, other than changing the wake
distribution: stabilizing tip vortex cavitation or reducing the cavity volume.
Numerical fluid simulations around a propeller in noncavitating, unsteady conditions were also conducted, and the strength
of the tip vortex along the circumference and its derivative were examined. As a result, the phenomena were parameterized
by the time derivative of the strength of the tip vortex, and if it was higher than a threshold value, the tip vortex cavitation
burst. Therefore, it is possible to predict the occurrence of the bursting phenomenon by numerical analysis.
Received: November 6, 2001 / Accepted: January 24, 2002 相似文献
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