Final answer:
Cooling fans can be powered by a belt or it can be electrically driven.
Step-by-step explanation:
The cooling fan in a vehicle is essential for maintaining the appropriate operating temperature of the engine, especially when the vehicle is not moving. Besides being powered by a belt, cooling fans can also be electrically driven.
In the convection process used in vehicles, the cooling fan plays a crucial role by creating a forced convection scenario. It enhances the flow of air across the radiator, which helps in transferring the heat absorbed by the coolant to the air, thereby cooling the engine more efficiently.
Forced convection, as opposed to natural convection, involves an external force—such as a fan or pump—to increase the rate of heat transfer.
This is evident in car radiators where the convection process is driven by both the water pump that circulates coolant and the fan that aids in dissipating the heat. The result is a more effective cooling system that can handle the heat produced by the engine, even when the car is idling or stuck in traffic.