Computer modeling and investigation of vibration activity parameters of a centrifugal submersible pump

Abstract

The article considers the dynamic characteristics of one of the critical parts of a centrifugal pump, the rotor shaft, and the highest-level NASTRAN CAD module PATRAN was used for analysis. A calculated mechanical scheme has been compiled, and the force factors perturbing the rotor vibrations have been determined. The values of axial, radial and hydrodynamic forces acting on the impeller and pump shaft are found using analytical formulas. Under the given boundary conditions in the FE model and the chosen method for determining natural oscillations, the numerical solution of the equations of free and forced oscillations is found using the algorithms of the NASTRAN program. The determination of the rotor's natural vibrations was carried out using the Lanczos method. To assess the dynamic stability of the shaft, the stress-strain state of the shaft, its movements under static loads, as well as the frequency and shape of the rotor's natural vibrations necessary for this assessment were determined.    The amplitude-frequency characteristics of the system for perturbation by external forces at the reverse and blade frequencies are determined and analyzed. Using the amplitude parameters of forced oscillations, the dynamic gain coefficient of the rotor was determined. Based on the amplitude-frequency parameters, the choice of the number of blades for the working centrifugal wheel of the pump is justified. The technique of computer modeling and determination of vibration activity parameters of the rotary shaft of a submersible centrifugal pump is presented.