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为解决海豚减阻的机理,本文给出了海豚体外的平面二维流动模型的阻力计算。计算结果表明,在该流动模型下,海豚表皮产生的波动以及由它诱导出的旋涡确有减阻作用。根据动量定理,仿照 K’arma’n 的方法,计算了海豚表皮所受的阻力。并进一步获得阻力与海豚速度、海豚表皮波波速、波长等物理量之间的关系。所得的这些理论结果表明:它们与国外对海豚或柔软壁减阻机理研究,中出现的一些规律相吻合,且能解释他们发现的而不能解释的一些现象。从而给出了海豚减阻原因的一个可能的理论解释。
In order to solve the mechanism of dolphin drag reduction, this paper presents the drag calculation of two-dimensional flow model of dolphin in vitro. The calculation results show that the fluctuation of dolphin epidermis and the vortex induced by it are indeed drag-reducing under this flow model. According to the momentum theorem, following the method of K’arma’n, the resistance of the dolphin epidermis is calculated. And further resistance and the dolphin speed, dolphin epidermal wave velocity, wavelength and other physical quantities between the relationship. The theoretical results obtained show that they are consistent with some laws found in the research on the drag reduction mechanism of dolphins or soft walls in foreign countries and can explain some of the phenomena that they discovered but could not explain. This gives a possible theoretical explanation for the drag reduction of dolphins.