PRE-NOZZLE FOR A DRIVE SYSTEM OF A WATERCRAFT TO IMPROVE THE ENERGY EFFICIENCY

摘要

PURPOSE: A pre-nozzle for a driving system of a ship is provided to reduce the loss of a propeller jet with a fin system installed in the pre-nozzle to generate pre-swirl and to improve the inflow of a propeller. CONSTITUTION: A pre-nozzle(10a) for a driving system of a ship comprises a water inflow opening and a water outflow opening. A fin system is located inside the pre-nozzle and is not arranged in an insertion section of the pre-nozzle. A propeller is not arranged inside the pre-nozzle. The pre-nozzle is asymmetrically formed along a circumferential direction.