Open Access Open Access  Restricted Access Subscription Access

Bioinspired Propulsion Mechanism Using Fin with Dynamic Variable-Effective-Length Spring

M. Nakabayashi, S. Kobayashi

Abstract


Since the propulsion mechanism in fluid using elastic fin like a caudal fin and a pectoral fin of fish is effective, many studies of elastic fin for propulsion in water and development of fish robot using elastic fin were carried out. However, the optimum elasticity of fin is not constant and changed by the movement task and environment, such as swimming speed and oscillating frequency. It is very difficult to exchange fins of the different stiffness while swimming. Thus, we aimed to develop the variable-stiffness fin, and made a fin with variable-effective-length spring. This fin enables its apparent stiffness dynamically. This paper describes the structure of the propulsion mechanism in fluid using fin with variable effective-length spring and characteristics of thrust force and efficiency. Furthermore, the relationship between the thrust force and the flow-field around the fin is discussed.

Full Text:

PDF

References


Morikawa, H. and Isshiki, N., "The Study on a Propulsion System by Fin Stroke", Bulletin of M.E.S.J., Vol. 8, No. 1, 1980.

Nakashima, M., and Ono, K. , Dynamics of a Twojoint Dolphinlike Propulsion Mechanism (3rd Report, Parameter Study for High Propulsive Efficency), Transactions of the Japan Society of Mechanical Engineers, Series B, Vol. 62, No. 602, pp. 3607-3613, 1996.

Nakashima, H., Tokuo, K., and Ono, K., "Experimental Study of a Two-Joint Dolphinlike Propulsion Mechanism (2nd Report, Experiment of Self-Propelled Large Robot)", Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 66, No.643, pp. 695 –702, 2000.

Watanabe, M., Muramatsu, K., and Kobayashi, N., "Propulsion Performance of an Aquatic Mobile Robot Using Traveling-Wave Motion of a Flexible Fin (Relationship between Propulsion Efficiency and Flow Pattern)", Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 68, No. 665, pp. 188 –196, 2002.

Nagai, M., and Tanata, I., Hydrodynamics of Drag and propulsion (Learn for Ability of aquatic organism) (in Japanese), Ship & ocean foundation, pp.187-195, 1996.

Kobayashi, S., Nakabayashi, M., and Morikawa, H., Bioinspired Propulsion Mechanism in Fluid Using Fin with Dynamic Variable-Effective -Length Spring, Journal of Biomechanical Science and Engineering, Vol. 1, No. 1, pp. 280-287, 2006.

The Visualization Society of Japan, Handbook of particle image velocimetry, Morikita publication Ltd., pp.1-164, 2002.

Nishio, S.,and Nakamura, K., A study on the propulsive Performance of fish–like motion using waving model, Journal of the Society of Naval

Architects of Japan, Vol. 191, pp.17-24, 2003.




DOI: http://dx.doi.org/10.21535%2FProICIUS.2007.v3.600

Refbacks

  • There are currently no refbacks.