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The work is aimed at increasing the reliability, accuracy, information content and depth of the process of diagnosing the cylinder-piston engine group. For this, an automated diagnostic system has been developed, which includes a system unit with a monitor, special software for measuring and processing information, a measuring analog-to-digital module, adapters for connecting to the engine. The diagnostic system allows you to record the change in pressure of the cylinder for every degree of rotation of the crankshaft with an error that does not exceed 1.7%. Measurements are performed in test mode, when the crankshaft of the engine is scrolled with a starter, and strain gauges are screwed in place of spark plugs. The measurement results are presented in the form of diagrams, text and digital values. The system also allows you to save, reproduce and transmit diagnostic information in digital, graphic and text form.

In connection with the tightening of environmental standards, the leading manufacturers of marine low-speed engines are carrying out intensive work on their conversion to gas fuels. Due to the design features in this class of engines, only internal mixture formation is possible. For the organization of which two different approaches are possible. To date, only two are currently implemented. MAN started production of engines with gas fuel supply to the working cylinder under high pressure at the end of the compression stroke, and WinGD under low pressure at the beginning of the compression stroke. The analysis, performed by the authors, showed, that increasing the pressure before the gas supplying mechanisms to 3.5...6.0 MPa can reduce the residence time of the gas-air mixture in the working cylinder and reduce the likelihood of detonation combustion.

Operability and efficiency of transport diesel engines significantly depend on periodical diagnosis of its technical condition. The article considers the features of monitoring and diagnostic of transport diesel engines with the help of vibroacoustic analysis of high pressure fuel equipment and gas distribution mechanism. Functional scheme of diagnostic system and analytical method of TDC determination is described. Article gives an example of four-stroke and two-stroke diesel engines diagnosis. Also the article shows turbocharger speed determination and diagnosis with the help of vibroacoustic spectrum analysis. The main feature of the given methods is their high efficiency for diagnosis of transport diesel engines during operation.

Thermodynamic models based on the volume balance method for calculating the working process of an engine with spark ignition and internal mixture formation are presented. The single-zone model makes it possible to determine the pressure and average temperature of gases in the engine cylinder during the working process. The two-zone combustion model takes into account the change in the volume of the exhaust gases zone and the air-fuel mixture zone. The model makes it possible to determine the pressure of gases in the cylinder and the temperature in the zones under consideration when the air-fuel mixture is distributed over the entire above-piston volume at the moment of ignition. The three-zone combustion model takes into account the change in the volume of the exhaust gases zone, air-fuel mixture zones and air zones when organizing the stratification of the air-fuel charge, allows you to determine the gas pressure in the cylinder and the temperature in the zones under consideration.

This work delivers a rotordynamics model of a high-velocity impeller of a supercharged engine. This model includes a deformable shaft and deformable disk with blades. The bearings are considered to be compliant rather than rigid. The disk has a cantilever arrangement relative to the elastic supports. The stress-strain state of the rotor system is analyzed within a broad range of the dimensional parameters and the rotational velocities. The critical frequencies are studied for this system as well. It is demonstrated that the first two critical velocities of the cantilever rotor with a massive deformable disk can be modified effectively by appropriate choice of the distance between the supports and their stiffness. As a result the operational range of the rotating velocity can be detuned from dangerous resonance.