COMPUTER SIMULATION OF HYDRODYNAMICS AND HEATING NON-UNIFORMITY OF THE CYLINDER HEAD AND BLOCK DURING PRE-START THERMAL CONDITIONING OF AUTOMOTIVE ENGINES

Abstract

The paper presents the results of numerical simulation of heat transfer processes during the pre-start thermal conditioning of an internal combustion engine using a liquid heating system. The main objective of the study is to determine the spatial non-uniformity of heating within the engine components–particularly the cylinder block and cylinder head–and to evaluate the hydrodynamic characteristics of the coolant in the cooling system channels. The calculations were performed using the finite volume method combined with the k–ε turbulence model, which provides an appropriate balance between computational efficiency and accuracy under turbulent flow conditions. In the simulated preheating configuration, coolant circulation is organized with the inlet through the antifreeze outlet valve and the outlet through the drain pipe. The obtained results made it possible to identify stagnant zones forming in regions remote from the inlet pipe, which lead to significant temperature field non-uniformity. It was found that the temperature difference in the cylinder head can reach up to 20°C, while in the cylinder walls it can reach 30–40°C. The lower part of the engine crankcase practically does not participate in the heat exchange process, indicating incomplete heating of the engine during pre-start thermal conditioning. The total pressure drop in the system was calculated to be approximately 1658 Pa. The conducted study confirms the importance of CFD modeling as a key tool for comprehensive analysis of pre-start heating systems. Such simulations allow optimization of channel geometry, coolant flow schemes, and heat exchanger parameters, ultimately improving the efficiency of stored heat utilization and reducing the time required for the engine to reach its operating thermal regime. The obtained results can be further used in developing integrated models of the complete thermal preparation cycle for vehicle engines.