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

Abstract

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.