Improving the technical and environmental performance of piston engines by upgrading the fuel system

The article presents the results of an experimental study of the dispersion of superheated water through cylindrical channels and nozzles of piston internal combustion engines under different initial conditions. The advantages and disadvantages of modern diesel engine fuel systems are discussed in the article. The process of explosive boiling in relation to the fuel system of a piston engine is formulated and briefly described. A description of the laboratory setup and methods of conducting experiments is given in the article. The results of the visualization of sprayed superheated water through a cylindrical channel and through a diesel engine nozzle of 21/21 dimension are presented. The original scheme of the fuel system for a diesel engine using the effect of explosive boiling is proposed. Preliminary estimates have shown that the use of such a fuel system will increase the reliability of the combustion chamber elements of a piston engine, reduce specific fuel consumption (up to 2%) and reduce the amount of harmful substances in exhaust gases (an average of 12% compared with traditional fuel systems). © The Authors, published by EDP Sciences

Spectral analysis of gas-dynamic processes in the exhaust system of piston engine (82/71)

Batch machines are actively used in industry and energy. Internal combustion engines are a prime example of such machines. A feature of the operation of engines is that a certain amount of the working fluid is supplied to the working chamber, and upon completion of the process, the combustion products are removed from the chamber. Therefore, the aeromechanics of pulsating gas flows in the exhaust system significantly determines the efficiency of the engine. A distinctive feature of the processes in the exhaust system is their high dynamics (highfrequency pulsations due to the operation of valves with external disturbance from the turbine blades of the turbocharger). The article describes laboratory equipment (piston engine model), measuring system (main sensors and determined physical quantities) and data processing methods (spectral analysis). The boundary conditions during experimental studies are described. The aeromechanical characteristics of non-stationary flows in the exhaust system of the engine with and without a turbocharger are compared. Qualitative and quantitative differences in aeromechanics and thermophysics of processes in exhaust systems of various configurations are shown. A method for aeromechanical improvement of the exhaust system by creating an ejection effect is proposed. It was found that the ejection effect in the exhaust system of the engine leads to stabilization of the flow, an increase in air consumption by 6-12% and an improvement in reliability indicators by 1.11-1.74%. © 2020 Institute of Physics Publishing. All rights reserved.The work has been supported by the Russian Science Foundation (grant No. 18-79-10003)

Method of stabilizing pulsating gas flows in the intake system of a piston engine with turbocharging

Piston internal combustion engines (ICE) are the most common sources of energy among heat engines. Currently, most ICEs are equipped with a turbocharging system. Thermomechanical perfection of processes in the intake system largely determines the efficiency of engines. This article proposes a method of stabilizing the pulsating flows in the intake system by installing the leveling grid in the output channel of the turbocharger (TC) compressor. Studies were conducted on an experimental setup, which consisted of a single-cylinder engine and turbocharging system. A constant-temperature thermo-anemometer was used to determine the instantaneous values of the air flow rate and the local heat transfer coefficient. It has been established that the presence of a leveling grid in the intake system leads to a decrease in the turbulence number by up to 25% compared with the basic intake system (while maintaining the flow characteristics). It is shown that the installation of a leveling grid in the intake system of the ICE with TC also leads to a decrease in the heat transfer intensity by up to 15 % compared to the base system. The obtained data expands the knowledge base on the thermomechanics of pulsating flows in hydraulic systems of complex configuration. © 2019 Institute of Physics Publishing. All rights reserved.Russian Science Foundation, RSF: 18-79-10003The work has been supported by the Russian Science Foundation (grant No. 18-79-10003)

Features of thermomechanics of pulsating gas flows in intake systems with grooves in relation to turbocharged engines

Reciprocating engines (RICE) are widely used as heat engines to convert the chemical energy of fuel into mechanical work on the crankshaft. Aerodynamic and thermophysical processes in gas exchange systems significantly affect the efficiency of internal combustion RICEs. This article explores the possibility of influencing the gas dynamics and heat transfer of pulsating gas flows in the intake system by placing a channel with grooves. It is known that the presence of grooves in the channel leads to the formation of significant secondary vortices, which radically change the physical picture of the gas flow. The studies are carried out on a laboratory bench, which was a single-cylinder model of a turbocharged RICE. The system of measurements of basic physical quantities is described, taking into account their high dynamics in gas exchange systems. The experimental data processing techniques are presented. Primary data on the instantaneous values of the gas-dynamic and heat-exchange characteristics of pulsating flows are reported. It is established that the presence of a channel with grooves in the intake system leads to a decrease in the turbulence number by 40% and the intensification of heat transfer in the range of 5-50% compared with the basic intake system. A positive effect is shown in the form of an increase in engine power by 3% when using an upgraded system. © Published under licence by IOP Publishing Ltd.The work has been supported by the Russian Science Foundation (grant No. 18-79-10003)

Management of thermal and mechanic flow characteristics in the output channels of a turbocharger centrifugal compressor

It is known that the thermal and mechanical characteristics of the air flow in the output channel of a turbocharger compressor largely determine the effectiveness of the gas exchange processes quality of a piston engine. The studies were carried out on an experimental installation containing a turbocharger, output channels of different configurations, a measuring base, and a data collection system. It was found that stabilization of the flow in the compressor output channel leads to a significant increase in heat transfer intensity (up to 25 %) compared to the baseline pipeline while simultaneously reducing the turbulence number by up to 30 %. A more significant increase in heat transfer intensity (up to 30 %) was observed in the output channel of the compressor with grooves compared to the base channel while simultaneously increasing the turbulence number by up to 12 %. The proposed configuration of the output channels of the compressor can be used to intensify heat transfer for the natural cooling of the air during the intake process. The configuration with a leveling grid can be used to stabilize the gas-dynamic flow parameters in order to reduce the hydraulic resistance of the intake system of a turbocharged engine. © Published under licence by IOP Publishing Ltd.Russian Science Foundation, RSF: 18-79-10003The work has been supported by the Russian Science Foundation (grant No. 18-79-10003)

Transmission of thermal imaging by using infrared bundle based on silver halide solid solution

In this study, infrared bundle consisting of seven single fibres was manufactured. Experiences on transmission of the heated object thermal image was performed. The experimental data show that there is a fundamental possibility of thermal image transmission through the infrared bundle. © Published under licence by IOP Publishing Ltd