Numerical and Experimental Analysis of Thermal Boundary Conditions of Heavy Duty Diesel Engine Cylinder Head for Different Combustion and Fuel

This article analyzes the effects of combustion type (conventional diesel, dual-fuel, Aand gas-fueled), structural material (Ductile cast iron and Gray cast iron), and thermal boundary conditions on the sensitive points of the heavy diesel engine cylinder head. The target engine in this numerical and experimental simulation is a 12-cylinder V-shaped heavy-duty medium-speed diesel engine with a turbocharger. The experiment begins by installing 14 sensors on cylinder head No. A6 due to the worst working condition of the engine. 3D simulation is performed using the Finite Volume Method (FVM) within the framework of ANSYS-Fluent 2021 software under time-variable conditionsA(18 min) and k-epsilon turbulent flow model. The outputs are as follows: with an increase of 24% of the TGas, the temperature of the bridge between the exhaust-exhaust and Inlet-Inlet valves for the Gray and Ductile cast iron cylinder head increases by about 20%. Meanwhile, with an increase of 36% from the heat transfer coefficient (HTC), Athe temperature of the bridge between the valves increases by 14%. AThe ratio of the effect of changes in the TGasAto the HTCAon the temperature of the bridge between the valves is about 1.9 forAthe cylinder head made of ductile cast iron and about 1.8 for the gray cast iron. ASubcooled flow boiling will probably occur in the initial areas of the cylinder head, i.e. Asensors 2, 5, 8, Aand 11 due to the temperature increase above 447.33K.