The engine generates power by combustion. Combustion in the engine, produces heat where the heat is good for engine performance, but if the heat is overt it can damage the engine.
Therefore the engine has a mechanism to prevent overheating.
This mechanism is known as the engine cooling system.
Working Principle of Cooling System
Cooling system works by utilizing thermodynamics. This will transfer the heat, which has accumulated in the engine components, into the free air.
So, when combustion starts, heat begins to collect in the components near the combustion chamber. The cooling system will take the accumulated heat and release it into the air.
The mechanism for this to happen depends on the type of cooling system used.
In general, there are two types of cooling systems used in vehicles.
1. Water cooling system
Water cooling systems use coolant or water as a medium to distribute heat.
In this system, there is a water jacket. It is the water hole around the cylinder block and cylinder head. This hole will be filled by coolant.
So when the engine operates, heat will collect in the cylinder block. The water will circulate in the water jacket, so that the heat will spread to the water.
Then the water will be pumped into the radiator.
In the water cooling system, the radiator is the most important component. Because this is a component that releases heat into the air.
The working principle of the radiator, water will be divided into several thin hoses. Every gap in the hoses, there is a thin plate. Its function is as a heat sink.
So the heat carried by the water will propagate to the thin plate in the thin hoses gap.
After that, the cooling fan blows air through the radiator plate. So that the heat that has been divided into the plate will transfer to the air that passes through it. This is a natural event because the temperature on the plate is higher than the temperature of the flowing air.
This process is very fast, because the plates on the radiator are thin and if you count, the surface that contact with the air is large. So the cooling process can be fast.
This is the reason why the engine temperature is always stable even though the engine is running at high RPM continuously.
2. Natural cooling system
The second type is a natural cooling system, or some people call it an air cooling system.
The working principle is almost the same as the first type, but it's simpler.
The natural cooling system utilizes airflow to instantly cool the cylinder block. So the air will be blown (by the blower or naturally) into the engine block. Automatically, the heat accumulated in the cylinder block will move to the air stream.
But if we analyze, the cooling process will not be optimal because heat propagation is only focused on a few points that are directly exposed to air. In a closed engine condition, cooling will not be maximized.
Therefore natural cooling systems are used in small capacity engines such as motorbikes.
To maximize cooling, there are fins on the cylinder block. These fins will widen the contact surface between the engine and the air. So that the heat transfer process can be faster.