IDENTIFICATION OF PARAMETERS OF VIBRATION ELECTROMAGNETIC ACTIVATOR MECHANICAL SYSTEM USING LIMITING NEAR-RESONANCE FREQUENCY

Abstract

The relevance of the research is caused by the fact that vibration electromagnetic activators are effective devices for mixing suspensions, emulsions, preparing drilling fluids, liquefying highly viscous petroleum products. Armature has special design is a hydraulic rectifier. When the armature vibrates at near-resonance frequencies, deeply submerged jets are created in the treated fluid medium, which ensure high efficiency of mixing fluid medium and decrease in viscosity of petroleum products for a long time at relatively low energy consumption of the vibration electromagnetic activator. The resonant frequency of the mechanical system depends on spring stiffness, mass of the armature-activator, added mass of the fluid oscillating with the armature and viscous friction coefficient that determines the removal of energy from the vibration mechanical system. When the rheological properties of the treated fluid change, both the parameters of the mechanical vibration system and the type of frequency response of the vibration electromagnetic activator change. The method of organizing monitoring of changes in the rheological properties of a treated fluid medium with the vibration electromagnetic activator based on direct measurements, for example using viscometers, is suitable only for laboratory conditions and is not suitable for industrial implementation. According to the authors a more promising approach is based on solving an inverse mathematical problem when analyzing the vibration electromagnetic activator frequency response in particular limiting near-resonance frequency, one can get reliable estimates of the parameters of the vibration electromagnetic activator vibration mechanical system. It is convenient to use these estimates for organizing indirect monitoring of changes in the rheological properties of the treated fluid during the vibration electromagnetic activator operation and for improving the structure of the vibration electromagnetic activator automatic control system. The main aim of the research is to design the parameters identification of the vibration electromagnetic activator mechanical system using limiting near-resonance frequency method and to determine the method’s limits of applicability in high damping vibration mechanical systems. Research methods: ordinary differential equations, Laplace transform, transmissibility, frequency response, algebraic equations. Results. The authors have obtained the analytical expressions relating the limiting near-resonance frequency to the parameters of a vibration mechanical system. Based on the latter the system of algebraic equations was obtained. The method’s limits of applicability in high damping vibration mechanical systems are shown.

Keywords

• vibration electromagnetic activator
• mechanical system
• parameters
• identification
• resonance
• frequency response
• limiting near-resonance frequency