Research of Natural Frequencies of Fluctuations of Screw-Propelled Propulsion

Abstract

The paper is devoted to searching of frequencies and forms of eigentones of the screw-propelled vehicles with application of methods of the ANSYS Workbench 17.0 CAE program. The relevance of studying of frequencies of eigentones of screw-propelled vehicles increases in connection with development of the modern technologies of calculation by method of a terminating ultimate analysis which allow to carry out most precisely and quickly the modal analysis of large enough designs of the irregular shape. One of activators of the resonance phenomena, in the screw-propelled vehicle, is the screw-propelled propulsion unit with changing rotation speed. Generally, the rotor has a large number of frequencies of eigentones, however at their assessment from a position of impact on an action, minimum frequency has prime value. In theoretical calculations the rotor and screw propulsion unit was represented as the cylindrical envelope which is rigidly fixed from both ends. However, the actual form of a rotor and screw propulsion unit has more irregular shape, and does not get under the theory of flat envelopes. In this paper, the cases which are considering rotation of the screw-propelled propulsion and having tough fixing on end faces are considered. Comparison of natural frequencies of fluctuations of the screw-propelled propulsion some models and their comparison with driving frequencies is the result of the work.