Structure Improvement of Two-Cylinder Engine Cooling Water Jacket Based on Flow Field Simulation

The flow and heat transfer of the coolant directly affect the cooling performance, thermal load, and emissions of gasoline engine. The accurate estimation of heat transfer and temperature distribution within engines is crucial for studying thermal stresses and calculating engine performance. This study focuses on the design of a new cooling water jacket structure for a two-cylinder gasoline engine. In the novel structure, the coolant flows from the cylinder block to the cylinder head and then returns to the cylinder block, providing better cooling for the cylinder head. The three-dimensional simulation results show that the overall flow velocity of this structure ranges between 0.1 m/s and 3 m/s, which meets the design requirement of 0.1 m/s to 5 m/s. However, there are still some flow dead zones in this structure, which may lead to insufficient heat transfer. Therefore, the water jacket structure is further optimized. After optimization, the pressure drop between the inlet and outlet is decreased, and the velocity distribution becomes more rational. Both the flow velocity and the heat transfer coefficient meet the design targets. These results can provide theoretical guidance for the structural improvement of the water jacket and approaches to studying the flow characteristics of the coolants.