Keywords: diesel engine, bi-metallic two-piece pistons.

The article provides comparative analysis of thermal state of various pistons, such as non-cooled, lube oil-cooled from gallery space, steel, and bi-metallic two-piece pistons. Thermal fields in cross-sections of pistons in question are presented for type CHN 13/15 turbocharged engine with intercooler.

Keywords: vehicle diesel engines, loading cycles, damaging impact, constructional reliability.

The article presents the results of investigation into compression process in modern low-speed marine engine. The compression process is shown as adequately describable by linear, quadratic and cubic polynomials plotted in logarithmical coordinates. Compression polytropic index vs. cylinder piston-swept volume is considered.

Keywords: marine diesel engines, crankshaft.

An analytical method of prediction of crankshaft bearings' service life in marine diesel engines is offered, based on theory of random processes. The method allows estimation of probable values of wear rate and maximum wear in a bearing as functions of operating conditions, shape of crankshaft journal, and other factors subject to statistical laws.

Keywords: heat losses to cooling water.

Transcendental dependencies are offered for evaluation of heat losses to cooling water of 2- and 4-stroke engines as functions of combustion parameters, main cylinder dimensions and mean piston speed. Said dependencies are shown as having substantial generality and precision sufficient for practical analyses.

Keywords: crankshaft, indicator diagram.

Axial force in a connecting rod was calculated based on indicator diagram and crankshaft speed. Dynamic magnification factor for connecting rod load was calculated, as well as force and power of friction in piston-cylinder-unit. Friction losses were shown as dependent on crankshaft torsional vibrations.

Keywords: gas-dynamic processes.

The results are presented of gas-dynamic tests carried out on engine air inlet duct at various crankshaft speed. Air flow speed fluctuations in engine inlet air duct were measured on a motorless test stand with two DC heat-loss anemometers during suction phase and after inlet valve closure.

Keywords: power turbines, hybrid turbochargers, turbo-compound systems.

Trends are reviewed in the development of heat recovery systems of combined power plants including generators driven by engines with steam & power turbines and hybrid turbochargers. Data are presented concerning fuel efficiency and power range of various turbo-compound systems.

Keywords: marine engine, turbocharger.

The article describes the results of tests carried out on a motorless stand with a view to study counteraction between a turbine section and inlet duct of a turbocharger of high-powered marine engine. Quantitative assessment was offered of mutual influence of said system's components. It is demonstrated that turbine section nozzle passages should be shaped taking account of their respective positions in the inlet duct, in order to enhance turbocharger efficiency and reliability.

Keywords: bush bearings, hydromechanical characteristics, micropolar liquid.

A method is discussed of analysis of hydromechanical characteristics of bush bearings, lubricated with micropolar liquids and exposed to combined loading. The method in question is based on Oehringen's theory of micropolar liquid flow. Effective temperature of lube oil layer in a finite length bearing is found from a heat balance equation. Several test problems were solved; furthermore, influence of micropolar oil parameters on hydromechanical characteristics of engine bearings was evaluated.

Keywords: marine diesel engines, nozzle block, turbochargers.

The results are described of a study dedicated to the efficiency of 9TMS410 and 12V40/54A mid-speed heavy-fuel engines operating at partial loads vs. nozzle block cross-section area of their respective turbochargers types VTR320 and VTR321. A method is offered to reduce fuel consumption at partial loads through changing nozzle block cross-section area.

Keywords: diesel engines, measurement.

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