http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ship's Propulsion Using The Weis-Fogh Mechanism
Michihisa, Tsutahara,Takeyoshi, Kimura,Ro, Kideok 國立統營水産專門大學 附設 水産科學硏究所 1989 수산과학연구소보고 Vol.1 No.-
A two-dimensional model of the Weis-Fogh Mechanism, which is a mechanism of hovering flight of small insects, is applied to ship propulsion. A model of the propulsion mechanism consisting of one or two wings in a square channel is proposed. The thrust and the drag on the wing, which are defined, respectively, the force in the direction of progress of the ship and that of movement of the wing, are measured. The propulsive efficiency is calculated and is high when the moving speed of the wing is small compared with the advancing speed of the ship. A model ship equipped with this propulsion mechanism is made and working tests performed. The applicability of this propulsion mechanism to actual ships is expected to be good.
Unsteady Pressure and Force in the Discrete Vortex Methods
TSUTAHARA, Michihisa,KIMURA, Takeyoshi,RO, Kideok 國立統營水産專門大學 附設 水産科學硏究所 1989 수산과학연구소보고 Vol.1 No.-
This paper presents a calculation technique of the unsteady force, the moment, and the pressure distribution on a body or bodies in a two-dimensional flow when the discrete vortex method is used. The body surface is represented by discretized point vortices, and the force and the moment and obtained by integrating the pressure along the body surface. A mathematical formulation is presented for a flat plate, and this applied to the Weis-Fogh mechanism. This formulation is extended to arbitrary shaped bodies (a square cylinder as an example). The pressure distribution is obtained by estimating the argument of the logarithmic singularities. This method is direct in its derivation and applicable to the cases to which the Blasius theorem or the method using a control volume is difficult to apply. It is also shown that the force obtained by the present method and that by the above mentioned two methods have some difference. The difference is considered to be caused by the mathematical incompleteness of the discrete vortex method. An application of this method to arbitrary shaped bodies connected with each other is also briefly discussed.
A Ship Propulsion Using a Mechanism of Hovering Flight of Small Insects
TSUTAHARA, Michihisa,KIMURA, Takeyoshi,RO, Kideok,TAKAHASHI, Kunio 國立統營水産專門大學 附設 水産科學硏究所 1990 수산과학연구소보고 Vol.2 No.-
A mechanism of hovering flight of small insects which is called the Weis-Fogh mechanism is applied to ship propulsion. A model of the propulsion mechanism is proposed, and a model ship equipped with this propulsion mechanism was made. The model ship demonstrates that this mechanism works as a ship propulsion. The dynamic properties of the model are studied experimentally, and the effects of the side walls and a control of the opening angle of the wing and also an interaction of two wings are clarified. Propulsive efficiency is as high as 80%, and the wing moving velocity is low comparing with the advancing speed of the ship. A conceptual design is carried out.
조원도구,木村雄吉,盧基德,高橋邦雄 國立統營水産專門大學 附設 水産科學硏究所 1990 수산과학연구소보고 Vol.2 No.-
The effects of side walls of a channel in which a two-dimensional model of the Weis-Fogh mechanism is equipped are experimentally investigated. The effects of the elasticity of the spring which controls the opening angle of the wing are also studied. The thrust and drag increase after setting the side walls, but the efficiency of propulsion decreases when the opening angle is small ; otherwise it increases. By controlling the opening angle with the spring, the efficiency increases substantially, and it is cycle of the wing motion in the channel.
盧基德,조원도구,木村雄吉 國立統營水産專門大學 附設 水産科學硏究所 1990 수산과학연구소보고 Vol.2 No.-
The flowfield of a ship's propulsion mechanism consisting of two-series of wings in a square channel is visualized by numerical simulations using the discrete vortex method and by the hydrogen bubble technique. The simulations are performed by assuming that the separations occur at the trailing edges of the wings. The streak-lines and the time-lines agree well with experimental results. The flowfield is unsteady and complex, but the properties of the flow are clarified by numerical and experimental visualization. The time histories of the thrust and the drag acting on the wings are also calculated. These calculated values agree well with the previously obtained experimental values. The effects of the interaction of the wings are explained in terms of the circulations around the wings.