Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
The problem in the simplified consideration of discs in the rotor dynamics of large machines
Submission Author:
Lucas Fonçatti , SC
Co-Authors:
Danielle Raphaela Voltolini, Lucas Fonçatti
Presenter: Lucas Fonçatti
doi://10.26678/ABCM.COBEM2017.COB17-0009
Abstract
The models used to consider the elements that make up the rotor, especially in the case of discs, significantly affect the calculation of the rotor dynamic behavior of large machines. Components such as fans and flywheels, to quote, are commonly represented by means of rigid symmetric discs, however, this simplification is not always proper. A good example for this case is a radial flow fan whose design commonly has a hub (responsible for the interface with the shaft) and blades that are supported by radial rings. This typical geometry allows an asymmetric mass distribution with respect to the plane of the disc that supports the assembly, and this, along with the low stiffness of the component, may cause the influence of the disc in the gyroscopic effect greater than the expected on the dynamic behavior of the rotor. This paper investigates this behavior through numerical studies carried out using the finite element method, evaluating numerically the influence of this behavior to industrial rotor designs and showing that the consideration of asymmetric discs should be performed in those cases. Without that consideration, there is a risk to execute a project that will exhibit unanticipated behavior during its operation, such as the excitation of an unpredicted critical rotation.
Keywords
rotor dynamic, Large machinery, Electric Motor, Gyroscopic effect, Finite Element Method
