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In order to estimate decrease of ship speed in actual seas, it is important to calculate added resistance in waves with accuracy. Especially added resistance in short waves is one of the predominant factors inducing the decrease of speed for a large ship in relation to wave spectrum. Various calculation methods have been proposed for the added resistance in short waves. However those methods are proposed for blunt and low-speed ships, for example, tanker, bulk carrier, etc. Those methods give poor agreement with experimental data for fine and high-speed ships. To improve the estimation method, firstly numerical investigation on the effect of draft and frequency was carried out. Thereafter experiments of wall-sided models with motion fixed were conducted. From these results a new formula is proposed, which gives good agreement with the experimental results.

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Fluid transport is accomplished in a micro throttle pump (MTP) by alternating deformation of a micro channel cast into a PDMS elastomeric substrate. The active deformation is achieved using a bimorph PZT piezoelectric disk actuator bonded to a glass diaphragm. The bimorph PZT deflects the diaphragm as well as alternately pushing and pulling the elastomer layer providing displacement amplification in the PDMS directly surrounding the micro channel. In order to improve pumping rates we have embedded a PMMA ring into the PMDS substrate which increases the magnitude of the displacement amplification achieved. FEM simulation of the elastomeric substrate deformation predicts that the inclusion of the PMMA ring should increase the channel deformation. We experimentally demonstrate that inclusion of a PMMA ring, having a diameter equal to that of the circular node of the PZT/glass/PDMS composite, increase in the throttle resistance ratio by 40 % and the maximum pumping rate by 90 % compared to an MTP with no ring.