Detonation means the sudden and violent knocks experienced in an internal combustion engine.
By engineering means, this knock is set up by a high-pressure wave giving loud pulsating noise.
This occurs when it strikes against cylinder walls, cylinder head, and piston.
Here in this post, I am going to share the reasons behind detonation.
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A mild detonation will simply heat the engine but if it is severe, it may even result in fracture of the piston or other damages to the engine.
It also results in increased carbon deposits.
If it continues for a long time it may overheat the cylinder and spark plug so as to ignite the charge even before sparking and lead to pre-ignition.
These are some of the disadvantages. A properly designed combustion chamber will reduce it considerably.
Following are the main factors, which affect detonation,
01) The fuel used in internal combustion engine will considerably affect the chances of detonation.
Alcohol and benzol do not cause this. But it cannot be used due to its low calorific value and other objections to using as fuel.
Again alcohol cannot blend with petrol in the presence of water.
02) The detonation is also promoted by an increase in compression ratio.
The compression ratio at which it just occurs is known as the Highest Useful Compression Ratio.
Higher the chances with higher the compression ratio and the output will be lower.
03) If the carbon deposits are in the cylinder and used excessive sparking temperature, the detonation will be increased rapidly.
04) The position of the spark plug in a combustion chamber determines the distance the flame has to travel in order to reach the detonating zone.
Chances will increase with distance, more distance means more detonation.
A centrally placed spark plug works better.
The spark plug must be placed near to exhaust valve but the exhaust must be located away from detonating zone.
05) The Higher temperature of the walls of combustion chamber tends to raise the temperature combustion chamber tending to raise the temperature of detonation zone.
06) The rate at which the combustion of the portion of the fuel, which is first to ignite immediately after the application of the spark, also affects detonation.
Hence from the above description, you know it is dangerous for an internal combustion engine and must be removed or reduced.
Besides this information, you are suggested to read something more from below engineering books