Contra-rotating podded propulsor and its full-scale model tests

摘要

The global warming problem is concerned in the world. The Japanese Government has formalized the acceptance of Kyoto Protocol on 4th of June 2002. Under the Protocol, Japan has an obligation of greenhouse gas (CO_2 etc.) emissions reduction of 6% below 1990 levels for the first commitment period of 2008-2012. The restriction concerning the exhaust of NOx and SOx by ships is discussed in the International Convention for the Prevention of Pollution from Ships (MARPOL). Under the Ministry's of Land Infrastructure and Transport (MLIT) national research project named the Super Eco-Ship Project, the National Maritime Research Institute of Japan (NMRI) has been played major role of it since April 2001. Super Eco-Ship would embody a technical breakthrough in meeting certain requirements of coastal shipping such as reducing the burden on the environment and the logistics costs and improving the living and working conditions on board. Super Eco-Ship has highly efficient electrical propulsion system featuring the podded propulsor with contra-rotating propeller (CRP). Advanced concept and systems are applied in the research and development of the Super Eco-Ship. Flexibility in the arrangement of main engine and in the hull form design is realized by the electric propulsion system. New design tools based advanced concept and methodology are applied. Hull form design method by means of CFD simulation and CAD are performed to design optimum hull form for electric propulsion system. The high propulsive efficiency due to the combination with the optimum hull design and podded propulsor enables the reduction of CO_2 compared with the conventional ship. The podded propulsor with CRP enables drastically good maneuverability and flexible control system in ship operation as well as high propulsive efficiency. The pilot becomes easy operation in berthing time by the control system of the podded propulsor. In August 2004, a reliability test run of a prototype of the propulsor including the motors and sealing/bearing was completed in a dock. The practicality of podded propulsor with CRP was confirmed from this result. In this paper, the results of this tests is reported.