Research On Abnormal Similarity Analysis And Design Method Of Dynamic Model Of The Rotor System

Rotor system which is the main component of rotating machinery has the characters of complex structure and huge dimension. As a result, the research on dynamic characteristics of rotor system by model experiment becomes a significant research technology. However, studies on the similarity of rotor system are not comprehensive until now. Therefore, the dynamic similarity of normal model and abnormal model of rotor system are discussed by numerical simulation based on similarity theory. Aim at the problem in rotor abnormal model design, an approach for rotor model design based on optimization algorithm was proposed.Firstly, the similarity criterion between normal model and the prototype of rotor system was deduced based on dimension analysis. Then the dynamic similarity between them was analyzed by numerical simulation. What’s more, the influence of prediction accuracy was employed when bearing parameters are equal in normal model and the prototype of rotor system.Secondly, the similarity criterion between abnormal model and the prototype of rotor system was deduced based on equation analysis. Then the influence of abnormal ratio and the dynamic similarity between them was analyzed by numerical simulation. It is proved that abnormal model can also directly be used to predict the prototype’s dynamics.Thirdly, an approach for rotor model design based on optimization algorithm was given. The feasibility of this method is tested with a specific example. The method of converse thinking can be widely applied to the model design of various complex systems as it is proposed on the basis of general system theory.Finally, the natural frequencies and modal shapes are tested through the experimental modal analysis carried out by the normal model, abnormal model and the prototype of a double-disk rotor system. Then the dynamic similarity among them is compared. And the consistency and reliability of the dynamic similarity criterion of rotor system are verified.The outcomes of this dissertation improve the fundamental theories of the dynamic similarity of the rotor system. And they can be a theoretical support for designers to design rotor model with better dynamic performance.66figures,18tables,106references...