CFD Simulation Of Performance For Duct Propeller And Ship Wake

Ducted propeller is one of the special propellers, which take great care in domestic and foreign ship scientific researchers. Compared with normal propeller, ducted propeller has many advantages such as higher propulsive efficiency, larger propeller thrust and lower vibration in heave load. In order to The methods of theoretical investigation of propeller is potential flow theory methods,scientific researchers have done a great deal of research of duct propeller steady open water performance using lifting surface and surface panel coupling method for ducted propeller design.Lifting surface vortex lattice method and unsteady surface panel coupling method are used to calculate unsteady duct propeller which has made great progress.In order to overcome shortcomings of potential flow method, furthermore, with the development of CFD methods and improvement of commercial software many complicated engineering problems can be solved accurately. So CFD software is used more widely in the field of ship fluid mechanics.In this paper the flows around conventional propeller,ducted propeller and one type ship are simulated by PRO/ENGINEE software,FLUENT software and the mesh are generated by GAMBIT software.This thesis mainly deals with three aspects as follow:1) Model DTMB P4119 propeller and 19A duct and Ka4-70 propeller, adopt appropriate computational mode to simulate the 3D viscous flow of propeller, obtain its open water performance, then compare the results with experiment data to prove the reliability of computational mode.2) Model one seismic research vessel with bare hull and appendages,numerical simulation nominal wake.Compare the nominal wake in different speed, analysis the appendages struts and tail assembly how to affect the nominal wake. Compare the calculation with the model test of seismic research vessel with appendages, the calculation routine agree with experimental results,it is also within acceptable range of practical engineering applications.The comparison between calculated results and experiment data reveals that the numerical method adopted in this thesis can be used for simulation and prediction of the performance for propeller and ship, as well as obtain the flow pattern, velocity and pressure distribution which cannot achieve by using traditional methods. That will undoubtedly decrease the works of experiment and increase working efficiency.