Pylyov V. Determination of combustion chamber heat insulation effect on internal combustion engine operation performance

Processes of heat exchange among an in-cylinder medium and an internal combustion engine combustion chamber wall. Determination of effects of the combustion engine heat insulation on engine operation performance criteria by means of taking into account of nonstationary high-frequency heat exchange among an in-cylinder medium and a piston, carbon deposit presence on a combustion chamber surface and fuel film evaporation features. Experimental methods have been applied for the diesel cycle identification, determination of heat conductivity problem boundary conditions of the piston top-land, estimation of thickness of carbon deposit layer generated on it. The diesel cycle simulation have been performed using the model of mixing and combustion by N.F. Razleytcev. The methods of finite elements and differences are applied to compute stationary and nonstationary piston temperature state respectively. For the first time the dynamic constituent of heat-insulation effect in the diesel combustion chamber at presence partually-dynamic heat insulation (PDHI) layer is determined. It makes 40-80% of the core material temperature decrease total value for different zones of the surface. For the first time nonstationary high-frequency temperature state of the coated piston combustion chamber surface in the regions of the presence of fuel film had been formed by long and short fuel sprays for the four-stroke automotive diesel engine under different operation conditions is estimated. Admissibility of piston temperature state simulation at PDHI effect presence using experimental indicator diagram had been obtained for the traditional engine is ascertained. It is required the engines with coated pistons and traditional ones efficiency comparison to be realized at carbon deposit amounts peculiar to their long-term exploration. Research results have introduced and are used at the PJSC "AVTRAMAT", problem research and development laboratory of the ICE chair of NTU "KhPI" and at teaching by disciplines "Heat transfer in ICE", "Perspective ICE constructions", at masters R&D work performing. Propulsion engineering.