Analysis Of Vibration And Acoustic Radiation Of Propeller Blades

In the field of ship building and marine engineering, the research of vibration and noise of under propeller is an important topic, it has tremendous influence on the ship’s stability, safety and comfort, especially warship’s stealth performance. Underwater noise of propeller can be divided into fluid-dynamic noise and blades vibration noise.At present, the research on numerical analysis of noise and vibration of propeller blades is pretty rare. Here we did research on the numerical analysis of noise and vibration of propeller blades in this article. The major work completed is as follows:Imported the data of propeller points to modeling software, then using CFD method to simulate the propeller open water performance in FLUENT. Calculated KT、KQ and7and compared with experimental datum. Turns out that these results are in good agreement, which has verified the reliability of CFD method.Based on the finite element method of elastic mechanics, calculated the natural frequency of propeller both in air and water. Written program codes to import results of force distribution of blade from FLUENT to ANSYS, then using the force to calculate response of the blade.Introduced the boundary element method to calculate the structure’s acoustic radiation. Based on the acoustic boundary integral equation, using the response results calculated by ANSYS as boundary conditions in Virtual Lab Acoustics to calculate the propeller’s acoustic radiation, such as the sound power level, sound pressure level and radiation efficiency level and so on. The calculated results peaked near the natural frequency of propeller blades, which verified that the methods used in this article to calculate natural frequency and acoustic radiation are correct and reliable.The calculated datum of the vibration and acoustic radiation of the propeller have provided theoretical basis to the prediction and optimizing of propeller’s vibration and acoustic radiation.