1. Heat Transfer from Engine to Coolant: The engine generates a tremendous amount of heat during combustion. This heat is transferred to the engine coolant (usually a mixture of water and antifreeze) via the engine block and cylinder head. The coolant circulates through passages within the engine, absorbing this heat.
2. Coolant Circulation: A water pump constantly circulates this heated coolant through the engine and then to the radiator.
3. Heat Dissipation in the Radiator: The radiator is a large, thin metal structure with many small channels or tubes inside. These channels are filled with the hot coolant. The radiator is designed to maximize its surface area, allowing efficient heat transfer to the surrounding air.
4. Airflow: Air is drawn through the radiator by a fan (often electric, sometimes driven by a belt from the engine) or by the vehicle's forward motion (at higher speeds). This airflow comes into contact with the hot coolant within the radiator's tubes.
5. Heat Transfer to Air: Heat from the coolant is transferred to the cooler air flowing through the radiator fins. This heat transfer happens through conduction (heat transfer through direct contact between the coolant and the radiator metal) and convection (heat transfer through the movement of the air). The large surface area of the radiator fins significantly increases the efficiency of this heat transfer.
6. Cooled Coolant Returns to Engine: After the coolant has released a significant amount of heat to the air, the now-cooler coolant flows back to the engine, continuing the cycle.
In short, the radiator acts as a heat exchanger, transferring heat from the hot engine coolant to the cooler ambient air. The effectiveness of this process depends on several factors, including the design of the radiator, the amount of airflow, the coolant's properties, and the ambient temperature.
