The article presents the acoustic method of marine low-speed engine turbocharger parameter estimation under operating conditions when a prompt assessment of instantaneous turbocharger speed and rotor vibration level is required. The method lies in the analysis of the acoustic signal that is generated by the compressor of the turbocharger with the diesel engine running under load. The spectral analysis reveals that the compressor blades generate acoustic oscillations that are always present in the overall acoustic spectrum of the turbocharger regardless of its technical condition. The harmonic components corresponding to the blades can be detected in the spectrum using the limit method. The calculated instantaneous turbocharger speed makes it possible to analyze the main harmonic amplitude in the spectrum. The method presented in this paper helps eliminate discrete Fourier transform (DFT) spectral leakage so that the amplitude of the main harmonic can be estimated. Further analysis of the amplitude of the main harmonic allows for efficient estimation of the turbocharger rotor vibration level when in operation. The method can be practically applied by means of a smartphone or a computer that has the dedicated software installed. The proposed method lays the foundations for a permanent monitoring system of turbocharger speed and vibration in industrial and marine diesel engines.

The paper analyzes the deformation of the connecting rod stem with buckling due to water ingress into the internal combustion engine cylinder (the so-called hydrolock). A method is presented that has been developed to perform calculations of stem deformation in the process of compressing air with liquid in an internal combustion engine cylinder. The method is based on solving a system of differential equations for pressure and temperature in the cylinder, followed by calculating the compression force acting on the connecting rod. A carried-out simulation of the compression process demonstrates the dependence of the air pressure in the cylinder, the stress and the strain of the connecting rod on the fill ratio of the combustion chamber with liquid. The calculations performed according to the classical theory of resistance of materials have shown that the connecting rod with the buckling of the stem begins to deform when the liquid fills the combustion chamber to a minimum of 80%. With the increase in the amount of liquid, the deformation of the conrod increases, and when the level of liquid filling is so significant that it exceeds the volume of the combustion chamber, the conrod stem deformation reaches extreme values. It is shown that under these conditions after the hydrolock occurs the engine may fail due to the piston wedging the crankshaft in the bottom dead center position.

This paper investigates the process of destruction of parts of the connecting rod-piston group of the engine due to hydraulic lock after the ingress of liquid into the cylinders of the engine. Comparing expert data on actual engine destruction due to hydrolock with existing estimation models has made it possible to identify a number of significant contradictions affecting the objectivity and accuracy of the destruction assessment. To resolve the existing contradictions, a mathematical model for reconstructing the destruction of the connecting rod-piston group of the engine during a hydraulic lock has been improved. Unlike the existing ones, the model makes it possible to take into consideration not only the static deformation of the connecting rod but also to give a comprehensive assessment of the deformations of the connecting rod, piston pin, and piston at different volumes of hydrolock fluid. Underlying the model is the hypothesis assuming that the deformation of the piston pin under excessive load caused by hydraulic lock leads to the emergence of tension and an increase in the friction in the mated pin-piston. The calculation from the condition of differential change in the amount of friction in the mated pin-piston produced a satisfactory result that does not contradict the practical data and has confirmed the working hypothesis. By calculation, the onset of the destruction of engine parts during hydrolock at a pressure in the cylinder close to 17.3 MPa, at a crankshaft angle of about 346°, was revealed. In addition, it was found that in the case of violating the operating conditions, due to friction, the mated pin-piston is exposed to the lateral force on the skirt that reaches 17.2 MPa, which exceeds the permissible one, calculated according to known procedures, by 2.8 times. The results reported here are confirmed by known practical data, which makes the devised model applicable to the practice of expert studies into the causes of engine malfunctions when violating the operating conditions of a car

73 with the classical method of a calibrated starter using the correlation of electric starter shaft torque while motoring the crankshaft with the diesel engine torque. Some standard motor oils viscosity-temperature characteristics regression dependences in the range of starting temperatures and the empirical torque dependence on the oil kinematic viscosity are determined. As a result, a table of equivalent cold start temperatures was created using variable loads during HSSDDE startup. On the basis of the results of the experiment the theoretically calculated values of equivalent cold start temperatures for other oils used in the operation of HSSDDE are given. Specified range of variation of the cold start equivalent temperature factor for further polyfactorial investigation of the HSSDDE start process, which will take values of 0 °C, 5 °C and 10 °C.

This paper considers the mechanism of malfunction of internal combustion engines that implies the accelerated local wear of parts in individual cylinders as a result of uneven distribution of dust particles that pass through the air filter in the intake system. In order to acquire quantitative data on the effect of the structure of the intake system on the redistribution of dust in engine cylinders, the two-phase flow of air with dust particles in the standard elements of the intake system was mathematically modeled. ANSYS software package was used to solve the problem. A simulation technique was devised in which the airflow was first calculated to determine the boundary conditions for dust, after which the flow of air with particles was calculated. The calculations were carried out in a range of air velocities of 5‒20 m/s in branching channels with diversion angles of 45°, 90°, and 135° for the most characteristic particle sizes of 5‒30 µm. It has been estimated that dust particles deviate from the air streamlines by inertia and can slip through the lateral drain the stronger the larger particle size, diversion angle, and velocity of air. The comparison of the simulation results with experimental data confirmed that in the intake system of some engines, due to uneven particle distribution, there is local abrasive wear in one or more cylinders, which can significantly reduce the resource. This paper shows the need to take into consideration the centrifugation and redistribution of dust in the intake systems during the design, modernization, expert studies to determine the causes of faults associated with faulty operating conditions, as well as to clarify the regulations for the maintenance of existing engines.