The Design Strategy Of Low Noise Propeller

The propeller noise is one of the main noises of ship. It has no effect on its hydrodynamic characteristics. But it can affect the comfortable degree of the crew and passengers and even be harmful to the people’s health. More importantly, the propeller noise would affect the consealment of the modern warships. Therefore, the propeller noise has always been a hot topic for the researchers at home and abroad. The vibration charateristics, hydrodynamic characteristics and the soundradiation of the propeller are analyzed by numerical calculation based on the finite element method(FEM) and the boundrary element method(BEM). Details are as follows:1) The2D coordinate values are converted to the3D coordinate values according to the paraments of the propeller. The3D propeller model is established. The open water performance of the propeller is analyzed. The accuracy of the modeling method is verified. It shows that the numerical method used for the propeller hydrodynamic performance analysis is suitable and has a high level accuracy.2) The effects of the rotating, damping and coupling on the vibration charateristics of the propeller are studied. The culculating methods are verified. The effects of the rotating and damping on the vibration charateristics of the propeller is analyzed by the finite method. The effect of the coupling on the vibration charateristics of the propeller is analyzed by the coupled modes analysis method.3) The propeller sound radiation is studied as the excitation at different positon on the blades. It turns out that the SPL is the lowest with the excitation acting on the root of the blade and the SPL is the highest when the excitation acts on the tip of the blade. The unsteady hydrodynamic characteristics of the propeller is culculated. The pulsating pressure of the propeller is set as the excitation on the propeller. The respond of the propeller is calculated. The sound radiation of the propeller is analyzed by the direct boundary element method.4) The sound radiation of the propeller is analyzed as the materials and the geometric parameters of propeller are changed. The design stratedies of low noise propeller are given based on the comparasion anslysis.The stratedies of low noise propeller are given based on the studies all the above. It has important significance for the development of the efficient, low vibration and low niose propeller.