ABSTRACT
Working in the above direction Belibassakis & Politis (2013) proceed by substituting the passive pitching setup by an active pitching control, using a proper control mechanism and a pitch setup algorithm, on the basis of the (known) random motion history of the wing. As illustrated in Figure 1, the wing undergoes a combined transverse and rotational oscillatory motion, while the ship is steadily
1 INTRODUCTION
Greening of sea transport has been recognized to be an important factor concerning energy saving and protection against global warming and climatic change effects. Ships transport 90% of the world’s cargo and the engines on these vessels burn low-grade oil producing large amounts of air pollution. In this direction, the optimization of propulsive efficiency of ships operating in realistic sea states is considered very crucial; see for example Belibassakis et al. (2013) where the effects of wave added resistance and of ship motions on the operation of the propeller are considered. On the other hand, evolution of air and sea creatures, through million years of natural selection/optimization, arrived to the flapping wing as their single propulsion system. Also, research and development concerning flapping foils and wings, supported by extensive experimental evidence and theoretical analysis, has shown that such systems at optimum conditions could achieve high thrust levels; see, e.g., Triantafyllou et al. (2000,2004), Taylor et al. (2010), von Ellenrieder et al. (2008).
