Energy-Saving Devices in Ship Propulsion: Effects of Nozzles Placed in Front of Propellers

The hydrodynamic effect exerted by a nozzle placed in front of KP505 propeller on the propulsive performances is studied using extensive numerical simulations. influence NACA 0015 with chord length 0.3 diameter, D, mounted at 0.2 D plane for various range relevant diameters and different angles attack. A detached eddy simulation (DES)-based hybrid technique implemented ISIS-CFD finite volume solver Numeca’s FineTM/Marine environment proposed to fit purpose. Systematically conducted simulations have proven that net thrust reflecting overall drag, which includes nozzle, depends duct size. presence determines two regions inflow into propeller. One inner region where high-speed flow exists because contraction duct. other outer decelerates due wake. Lower- higher-pressure coefficients suction pressure sides, cover significantly wider area than those case without leading therefore greater torque. existence critical attack angle magnitude relative axial force becomes maximum smallest diameter has been noticed.