The purpose of this paper is to study the problem which a propulsion method by fin stroke like fish and dolphins is practically applied to the propulsive system of ships. The Fin Ship, which mounts a dolphin-style oscillating wing apparatus under the bottom of the ship, is made for trial and a feasibility test from the engineering stand-point is carried out.
The Fin Ship has the following merits; it is free from rolling and pitching of the ship; the danger of one being involved into the rotating screw can be eliminated; contamination of water resulting from the screw stirring up water can be prevented; the propulsive efficiency which gives about 66% in low frequency range is high compared with that of conventional small propellers.
It is found that this new propulsion system has great possibility to be applied for low speed ships.

View full abstract

Particle-diameter distributions of soot in laminar diffusion flames are sampled, rapidly quenched, and analyzed using the electron microscopy. They are measured together with the data of soot mass concentration, gas species concentration and temperature in the same flame.
The results obtained are as follows.
The forms of soot taken in the film becomes the monodispersive particle and chainlike clusters at all positions sampled in the flames. The curve of particle-diameter distributions forms the lognormal distribution. The value of standard deviation (ln^σ_g) are estimated to be about 0.4-0.6 for the monodispersive particle diameter and volume-equivalent sphere diameter obtained from clusters, and 0.2 for non agglomerated soot particles. Particles number concentration in the agglomeration are decreased by the dilution of the fuel with N₂gas.

View full abstract

A transport system in Japan has faced many new challenges since the first oil crisis took place in 1973. Besides the limited oil supply, there is also other requirement such as making up an optimum system. But the method of evaluation of transport system does not attain the perfection yet, and an evaluation of energy system is pointed out to be confused. It is extremely important to understand that transmission is widely different from consumption in evaluation of energy system, and also important to develop a mathematical model that evaluates a transport system. Realizing this point early, a study of this subject has been commenced and recently theoretical results have been obtained. In this paper, considering a simple model of energy flow, a mechanism of hierarchical structure of transport systems has been analyzed.

View full abstract