The development of a dependent mathematical model of dielectric properties of an engine oil to the concentration of soot formation

Abstract

The frequency of engine oil replacement reaches 150 thousand km for modern trucks, which increases the load on the lubrication system, leads to an increase in the level of contamination and to a greater level of oil degradation. The accumulation of dirt in the oil and, above all, soot leads accelerated wear of bearings, valves and camshafts, and increases the rate of formation of sludge and deposits on the piston rings. All this significantly reduces the engine life. The purpose of the work is to estimate the soot concentration in engine oil by its dielectric parameters measured by the waveguide method. To study the dependence of the dielectric parameters of engine oil on the soot concentration, the transmission line method was chosen and an installation was created that allows measuring the signal amplitude in a given frequency range. Tests performed on various engine oils at soot concentrations in the oil from 0 to 1.06% allowed us to identify the most optimal frequency regions where high sensitivity of the method is achieved. The nature of the change in the dielectric constant of engine oil with an increase in the concentration of soot in it is established. Diagnostic indicators such as the frequency of peak peaks and the signal amplitude at the optimal frequency are identified. Mathematical models of the dependence of the peaks amplitude and frequency on the soot concentration in engine oils are constructed.