Design And Hydrodynamic Performance Calculation Study For Screw Propellers Of High-Speed Vessels

Marine screw propellers are the most widely used among the numerous propelling forms in the world at the present. The variety and type of propellers develops and updates as world technology progresses. And as the electronic science and technology develop continuously, the study for the performance of propellers no longer stands on the trials of models in towing tank. The birth of various kinds of simulating software makes performance test much easier, more convenient and more efficient. The purpose of this paper is to design and analyze a high-speed propeller.Firstly, this paper collects the original data which includes velocity and power to make an atlas design for the propeller. The resistance of the vessel can be calculated by formulas and the basic conditions of preliminary design can be interpolated. Then what has been obtained can be secondary data to design the geometrical form and design speed.Secondly, transform the coordinate values of all the points in the 2-D graph to the coordinate values needed by the 3-D graph and model the propeller with the points by the software GAMBIT. Then combine the hub and the blade in the model on the basis of the relationship between them. Generating grid and setting boundary condition can be made after finishing modeling. And these are prepared for FLUENT to predict the performance of the propeller.Finally, FLUENT is used to calculate the model. And the simulation and analysis without considering cavitation of the open-water performance of the propeller can be done with the previous obtained data. A comparison can be done between the trial values and the calculated values. While in the actual condition, high-speed propellers can cause cavitation inevitably. Therefore, the curve of open-water performance of the propeller with considering cavitation should be computed.While the model is being built, many approximative ways has been adopted because of some unwanted traits of the software FLUENT. Therefore, there are some errors in the calculation of the open-water performance while regardless of cavitation. When it comes to consider cavitation, the accuracy of the FLUENT regarding of cavitation should be tested, and I found it is hard to estimate the accuracy because of the boundedness of the data source obtained from the trial values. So the accuracy of the curve of open-water performance calculated by FLUENT when considering cavitation is to be further discussed. In addition, this paper only studies one of the two propellers on the ship without regarding of the mutual effect of the two. As a result, there are much more questions and tasks to study deeply.