New Selectively Absorbing and Scattering Heat-Insulating Coatings of the Combustion Chamber for Low-Heat-Rejection Diesel

This work is about heat-insulating coatings (HIC) used for combustion chambers (CC) of Low-Heat-Rejection Diesel Engines. These semitransparent coatings provide the necessary thermal regime to boundary walls and elements of CC, generation make up 50% of the radiant heat flow component. For this purpose model samples of porous ceramic materials based on powders of zirconium, silicon, aluminum oxides were offered as selectively absorbing and scattering coatings. These materials have transparent bands within the range of radiation wavelengths of an ignited gas mixture in CC of high-speed diesel engines. Simulation results show that there is a subsurface temperature maximum for ceramics under intensive visible and short-range infrared radiation. Internal CC walls do not achieve these extreme temperatures using these coatings. This allows us to provide an optimum temperature mode for CC which limits formation of toxic nitrogen oxides and increases the engine efficiency.