Without a cooling system, your engine would surely overheat within just a few minutes as the vehicle burns fuel. Early cars were "air-cooled" using no liquid coolant, but in pursuit of performance, engineers realized a robust cooling system was needed.
The car’s radiator acts as a heat exchanger, transferring excess heat from the engine’s liquid coolant into the air. The radiator is composed of tubes through which hot coolant flows, a protective cap that’s actually a pressure valve and a tank on each side to catch the coolant fluid overflow.
In addition, the tubes carrying the coolant fluid usually contain a turbulator, which agitates the fluid inside.
This way, the coolant fluid is mixed together, cooling all the fluid evenly, and not just cooling the fluid that touches the sides of the tubes. By creating turbulence inside the tubes, the fluid can be used more effectively.
A heat exchanger is a device which is used to dissipate heat from a piece of machinery, and in turn heat up the air around itself.
Simple, air-cooled engines and many electronics today rely on thin metal fins known as heat sinks in order to draw air to cool themselves. On engines, the heat sinks are typically wrapped around the cylinder head near where the combustion chambers are located.
An air-cooled engine block is very simple to produce but does not cool efficiently enough to keep up with modern performance demands. This is why the typical automotive cooling system today uses a water cooled system, containing a car radiator, engine coolant and a water pump which pressurizes the hot liquid through a series of radiator hoses and tubes.
The radiator in a car works on the exact same heat transfer principles as a simple heat sink; the radiator contains hundreds of those fins.
The radiator inlet tank receives hot liquid from the engine block, which passes through these fins where cooling fans force air between them. As a result, the radiator cools hot liquid and returns it to proper operating temperature before sending it back to the engine.
Air cooling is accomplished because the heat sink has a high surface area relative to the components underneath when it comes to making contact with surrounding air. Sufficient airflow is also necessary to keep the system working efficiently, and it may also need a cooling fan which blows cool air over the fins and regulates temperature.