An Experimental Study on Propulsive Performance of a Newly Developed Non-ballast Ship with Buttock-Flow Stern Hull Shape

摘要

In Osaka Prefecture University,a joint project for developing energy saving tankers and bulk-carriers without ballast-water with several Japanese shipyards has been carrying out for these three years.In the developed ships,a buttock-flow stern hull shape for reducing its viscous pressure resistance and a slender hull shape with a rounder midship-cross-section for reducing viscous frictional resistance have been adopted.The buttock-flow stern shape,however,may cause low propulsive efficiency because of its weaker wake.In the present study,propulsive efficiencies for several kinds of buttock flow stern shapes are experimentally investigated by measuring the propeller thrust and the resistance acting on the hulls when the propellers are working.To understand the reason why the propeller efficiencies change for various stern shapes,wake measurements for these stern shapes are also carried out.On the bases of these experimental results,the best propulsion systems for the newly developed the non-ballastwater ship are selected.