Berezhnyi K. Models and tools for constructing a computer system for determining the rheological characteristics of technical fluids

The dissertation research is devoted to solving an actual scientific and practical problem - creation of a computer system for determining the rheological characteristics of ship's technical fluids with increased performance. The analysis of the current state of the systems of determination of coefficients of viscosity and rheological characteristics of ship’s technical fluids has been carried out which showed that over the past ten years ultrasonic systems have been distributed on the basis of piezoelectric transformer with visco-elastic coupling, the disadvantage of which is the discrepancy of processes in the measuring probe real processes at the tribotehnical units of the fuel equipment which allows them to be used only in nominal mode after carrying out additional tests, the term of which reaches two to three weeks. The classification of measuring probes with a piezoelectric drive has been proved that there are currently no measuring probes with a linear drive of a moving cylinder, the processes in which are similar to processes in the real tribotehnical units of the fuel equipment. For the first time an informational model of the computer system for determining the rheological characteristics of ship's technical fluids has been obtained, on the basis of which it is possible to construct automated systems for the investigation of ship technical liquids as well as control their preparation before being supplied to fuel equipment. The integration of the developed model into the general structure of the ship's operation was carried out which allowed obtaining a detailed information model of the system for determining and controlling the rheological characteristics of ship's technical fluids. The method of automatic determination and adjustment of rheological characteristics of ship's technical fluids is proposed which allows it to be used in computer systems with the possibility of changing the parameters of the system in real-time and on-line modes as well as to increase the efficiency of fuel preparation and reduce the amount of harmful emissions into the environment. Further developed algorithms for the automatic determination and regulation of rheological characteristics of marine technical fluids based on the proposed method for the automatic determination and regulation of the rheological characteristics of ship's technical fluids which ensures the fulfillment of all prerequisites for the hardware and software implementation of the computer system for the determination and regulation of rheological parameters of the ship's technical liquids. The mathematical model of the measuring probe of the computer system for determining the rheological characteristics on coaxial cylinders which are arranged vertically and driven on a linear piezoelectric motor has been improved which made it possible to get rid of the fluid flow and to determine the rheological characteristics not only in the flow but also in the laboratory conditions in the range of technological temperatures of the operation of the fuel equipment which makes it possible to conduct preliminary tests of the fluid. The design of the measuring rheometer of a computer system for determining the rheological characteristics of ship's technical fluids based on a linear piezoelectric motor has been developed and patented and experimental research has been carried out. As a result of the hardware and software implementation of the developed theoretical positions a model of the computer system for determining the rheological characteristics in the laboratory was created. A complex of comparative studies of lubricating oil for refueling the lubricating system of a low-turning engine and after 2000 hours of work, heavy fuel and comparative studies of diesel fuel without impurities and admixtures based on aluminosilicates has been carried out; confirmed the influence of the mass of the measuring probe on the movement time of the moving cylinder at its vertical arrangement and it is the movement of the moving piston from the upper extreme position to the bottom and the counteraction when moving in the opposite direction. Probability of the obtained results is confirmed by electronic simulation in SimInTech control systems simulator.