Experimental and simulation study of an automobile cooling system: Performance improvement using passive flow control

The performance of an automobile cooling system has substantial impacts on the engine's efficiency, fuel consumption, and CO2 emission. In this novel experimental and numerical investigation, a combination of full threedimensional car simulation, and one-dimensional modeling of the radiator along with the results of road tests on two car models, namely Vehicle A (the base car) and Vehicle B, was used to evaluate and compare the performance of the vehicles' cooling systems. The effects of implementing a passive flow control as well as changing the angle and geometry of the air deflectors on the cars' performance were investigated. The simulation utilized the K-epsilon (k-epsilon) turbulence model, while the experimental section involved standard road cooling tests. The results show that modifying the air deflectors in Vehicle B enables quick cooling of the system by controlling the air flow rate moving toward the radiator, which increased the air mass flow rate through the condenser and the radiator by 13% and 21%, respectively. Also, the radiator inlet water temperature decreased by about 1.9 degrees C, and the fuel consumption was reduced by approximately 0.5% under the New European Driving Cycle (NEDC) conditions, which decreased the greenhouse gas emissions, namely CO2 by about 0.9%.