Sail application in a handy-sized bulk carrier

摘要

With hydro-carbon based energy sources like oil and coal fast depleting application of other sources of energy are being tried in specific areas, eg, wind energy can be harnessed in the sea to supplement the power generated by the main machinery of a ship, to save fuel consumption. In sail-assisted ships, where the main source of power comes from the main engine, a part of the required thrust to move the ship ahead can be generated by the sail. Though this technology has already been developed and used by several countries, data on the experimental results or on ships built have not been published for commercial reason. In-house research is therefore necessary to develop this technology. NSDRC has carried out a study on the application of sail on a handy sized bulk carrier and have conducted wind tunnel tests on several scaled models. An economic study also has been conducted to check the viability of sail application, with spurt in oil price in the international market, this technology will emerge as the one to be adopted all over the world in near future. Selection of the right route, where favourable wind is available almost throughout the year, is crucial for the success of sail assisted propulsion. Other important parameters to be decided are: size of the ship; ship's cargo handling gears and their locations; size, number and locations of the sails on the ship. Strength and structural weight of sail and cargo handling gear location/operation influence the sail dimension. Proper selection of sail span, chord and camber is crucial to achieve better sail generated thrust. Other important design parameters are, maximum wind speed up to which sail can be operated and system for sail rotation and furling/unfurling. Sail weight is to be kept low, to reduce the power requirement for its operation It is seen that further research is necessary in areas like sail with better thrust generating property, lighter sail mast and 9n use of special design of main machinery, where specific fuel oil consumption remains low at partial loading.