Numerical analysis of fluid seals applied to rotating machinery

Abstract

The study of rotordynamics machinery is very important in the context of solids mechanics because the subject has a prominent position in the study and applications of machines and structures. The presence of a rotating component transmitting power can lead to a series of problems, therefore, it is very important for a mathematical development that allows the simulation of the operational characteristics of those machines and understanding of the phenomena related to their dynamics. The rotor dynamics analysis intends to predict the behavior and to identify deviations through the dynamic responses of the set, providing traces of malfunction or failure diagnosis, minimizing the risks of subtle halts of the system. The dynamic study of rotating machines must be done considering the interaction between the components involved in their construction, for example, bearing, fluid seals, rotors, shafts, and supporting structures. In this context, this project has as its purpose the determination of plain seals' physics parameters, which must be added to the global model of rotating systems. The difference between the pressure on the inlet and the outlet of mechanical seals will be obtained through the governmental equations for liquids flowing in annular seals, and by the Bernoulli equation, utilizing the finite volume method. The equivalent stiffness and damping coefficients will be estimated by the least-squares method. The Moody and Blasius friction factors will be compared and the results obtained will be validated through direct comparison with the values presented in the literature. The results of this project will be applied to the global modeling of a rotating machine, in order to make the analysis of the rotating set more complete.(AU)