Research On The Dynamic Characteristics Of Marine Centrifugal Fan

After years of continuous improvement, the vibration and noise of marine centrifugal fans have been reduced, but they still can not meet the requirements of some modern ships. Now in the testing process we find that, the noise and the vibration of a prototype marine centrifugal fan are with great amplitude, which may affect the normal operation of other equipments around. Trough the improvement of volute and worm flow characteristics as well as the laying of the damping sound-absorbing material, testers have managed to control noise to the standard range, but the vibration amplitude is still large.In order to understand the actual vibration characteristics of the fan, first of all, the application and research of modal analysis theory and testing methods will be research and analysis to determine the method of this study.Subsequently, pre-compute finite element models of impeller and fan using ANSYS for a preliminary understanding of the vibration, also as a reference for physical testing.On this basis, experimental modal analysis (EMA) test will done for the impeller and the fan. By comparing, matching and analysis of the data, the dynamic characteristics will be studied, as well as the assessment of the effectiveness of the two methods and finite element model updating.Finally, using operational deflection shapes (ODS) testing method again on the impeller and the fan., by contrasting the method of the test, the set of data results, accuracy and validity, the advantages and shortcomings of the ODS method will be analyzed.