A reciprocating engine system works on converting one form of energy into another. While doing such 60-70% if the energy gets waste as heat and if this heat is not rapidly removed then the cylinder might get over heated and lead to whole engine failure.
Air cooling is the method of dissipating heat. Air-cooled engines rely on air circulation directly over the hot parts of an engine to cool them. In an air cooling system, the outer surface of the reciprocating engine is cooled by flowing air over it. The metallic fins are cast in order to increase the heat transfer. These fins help in increasing the heat transfer area and henceforth the heat transfer rate. This cooling system is simple, reliable and free of maintenance and with no cost operation. This is very efficient for small automobile engines.
1) It is used in small engined automobiles like that of motorcycles, scooters; airplanesand fighter tanks which are high speed vehicles and gives a good velocity to the air to cool the engine.
2) It also finds its use in small immobile engines used for agriculture and industries.
- Air cooling system simplifies the engine design.
- Since no requirement of cooling pipe radiator or fan or liquid cooling jacket, the engine weighs less.
- Since the cylinder wall temperature is very high, the power output from engine is more.
- No danger of leaked coolant or freezing of coolant.
- The engine can be quickly and simply installed, assembled and dismantled.
- And the engine is perhaps maintenance free.
- Non uniform cooling of engine.
- Owing to high wall temperature, the compression ratio of the engine is limited.
- Compared to water cooled engine, the volumetric efficiency is lesser.
- Creates aerodynamic sound or noise.
- Since it has small capacity of heat dissipation it can be used only in small size engines.
How air cooling system different from liquid cooling system(LCS).
An LCS circulates liquid via small pipes in a heat sink that is attached to the processor. As liquid passes via the heat sink, the heated processor transfer heat to the cold liquid. The warmed liquid is then cycled to a radiator where it gets released into the ambient outside air. Te cooled liquid then travels back to the system.
Some advantages and benefits of a LCS over air cooling system include more efficient cooling and less noise when the system is on run. The disadvantage is that liquid cooling can be quite complex, costly, and it requires more maintenance.