Study On Hydrodynamic Performance Of Container Ship With Podded Propulsor Based On Cfd Method

Podded propulsor, called POD propulsion, is a new type of ship propulsion system, which could save the ship space, decline the noise and the vibration, increase the efficiency, and improve the payload capability. Therefore, POD propulsion plays an important role in the wide market application and military value. In this background, Poland B573 container ship is studied with the methods of CFD and numerical analysis. So the steady and unsteady hydrodynamic performance of POD propulsion could be researched.A novel ship hull form is proposed in this study, established by MAYA software with NURBS (Non-Uniform Rational B-Splines) surfaces, which makes conventional B573 hull form integrated Pram stern with a POD propulsor. A meshing method of modeling ship flow field is showed, and the resistance of the ship model is calculated depended on the ship speed. Finally, the wake flow field distribution on the propeller disk is analyzed. Comparing with the experimental results of Poland researchers, the results show that the resistance of the proposed ship model has declined about 10%, and the wake flow field distribution on the propeller disk becomes more uniform. Therefore, the phenomenon of uniform flow in stern improves the operation condition of the propeller effectivelyThe unsteady hydrodynamic performance of pusher and puller POD propulsion is simulated using fluid analysis software CFX with the method of moving mesh. In the X, Y, Z three coordinate directions, the simulation results of thrust and torque of the strut (rudder), POD, and propeller in a rotating cycle is discussed. It could be found that the oscillation of induced thrust and torque of the both POD configuration is periodic. In the same state conditions, the puller POD propulsion thrust is higher than the pusher POD propolsor, about 21.1%.For the puller POD propolsor integrated with Pram stern, the SST k-? turbulence model is used to calculate the hydrodynamic performance when the azimuth angle of the POD is deflected at 0°. The simulation results are compared with that of only the POD open water test which the inflow speed is the same as the ship speed. It is found that the thrust and torque are increased about 9-10% and the efficiency is increased about 1%, this is due to the influence of the wake flow field. Besides, the azimuth angle is studied on the influence of the POD propulsion hydrodynamic performance when the angle is 0°,5°,10°,15°,20°,25°,30°,45°,90°, 135°,180°. As a result, the thrust will reach the peak when the angle is 11°. Then the thrust will decline as the angle is increasing.