Assessment and enhancement of scooter thermal management via integrated 1D-3D simulation and experimental validation

To evaluate the cooling system design of a specific scooter model, an integrated computational methodology combining three-dimensional CFD simulations (STAR-CCM+) and one-dimensional thermo-fluid analysis (GT-Suite) is employed. This multi-scale approach enables a comprehensive assessment of cooling performance under typical operating conditions. The study focuses on optimizing two critical parameters: the air mass flow rate through the radiator core and the airflow velocity over the oil pan surface. Simulation results reveal that the coolant flow in the engine water jacket contains no significant stagnant regions, with velocities meeting established cooling requirements. In the original configuration, the radiator core intake air mass flow rate is 288 g/s, with a radiator inlet coolant temperature of 97°C. Airflow analysis indicates underutilization of the radiator’s upper section and low velocity regions along both sides. The oil pan surface experiences velocities between 0 and 1 m/s. After structural modification, the average air velocity across the radiator core increases from 5.5 to 7.54 m/s, and the air mass flow rate rises to 422 g/s. The oil pan surface velocity improves to 3–10 m/s. Thermal balance tests validate these enhancements, showing temperature reductions of 7°C for engine oil, 11°C for the cylinder head spark plug gasket, and 10.5°C for radiator inlet coolant. These results demonstrate a significant improvement in cooling performance, confirming the effectiveness of the integrated simulation-driven approach for scooter thermal management.