Reducing the Toxicity of the Exhaust Gases from the Internal Combustion Engine by Using a Ceramic Coating on Components of the Combustion Chamber

Abstract—One of the most pressing problems in piston engine engineering is the toxicity of the exhaust gases from internal combustion engines. Recently, the possibilities of using catalytic converters directly in the engine combustion chamber have been considered. Such converters can be created by applying special coatings to the surfaces of components of the combustion chamber. The most promising method is microarc oxidation, which allows the formation of ceramic coatings with high adhesive strength on aluminum alloy parts. Many experimental studies have demonstrated that such coatings can reduce the amounts of some components of exhaust gases in the combustion chamber. Since theoretical justifications for the use of such coatings to reduce the toxicity of exhaust gases have not been developed, the purpose of this work was the theoretical justification, development, and verification of a mathematical model of neutralizing exhaust gas components by coating combustion chamber parts by the microarc oxidation method. The developed mathematical model of reducing the amount of individual exhaust gas components in the engine combustion chamber takes into account many factors: geometric parameters and performance characteristics of the engine, as well as coating properties and exhaust gas composition. Based on previously obtained experimental data on an RMZ-551i engine, the developed mathematical model was verified over a wide range of speeds (2000–6000 min–1) and throttle opening values (25–100%). Verification by CO showed that the mathematical model allows calculations to be carried out with a sufficiently high convergence, at the level of an order of magnitude, and that it can be used for a preliminary assessment of the influence of various factors on the amounts of toxic components in engine exhaust gases.