What Is Detonation In Aviation?

What is detonation and what causes it?

Detonation, or engine knock, occurs simply when fuel pre-ignites before the piston reaches scheduled spark ignition. Detonation is generally caused by excessive heat, excessive cylinder pressure, improper ignition timing, inadequate fuel octane or a combination of these.

What does detonation mean?

: to explode with sudden violence. transitive verb. 1: to cause to detonate detonate a bomb — compare deflagrate. 2: to set off in a burst of activity: spark programs that detonated controversies.

What is detonation in SI engine?

Detonation is spontaneous combustion inside the cylinder AFTER the spark plug fires. It is similar to Pre-Ignition, but it is different. This causes a brief, but intense, spike in cylinder pressure. Detonation is also called an ” Engine Knock”, ” Knocking “, or “Pinging” because of the sound it makes.

How do you check for detonation?

Moderate to severe detonation could be noticed as engine roughness, vibration or loss of power and eventually engine damage. A pilot should always be looking for unexpectedly high Cylinder Head Temperatures (CHTs) or Exhaust Gas Temperatures (EGTs) which may be a sign that detonation is occurring.

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What is the difference between detonation and preignition?

Detonation: Detonation is the spontaneous combustion of the end-gas (remaining fuel/air mixture) in the chamber. It always occurs after normal combustion is initiated by the spark plug. Pre-ignition: Pre-ignition is defined as the ignition of the mixture prior to the spark plug firing.

What is difference between detonation and knocking?

In general, detonation is the cause and knocking is the after effect. Knocking is the result of the rapid combustion of end gas ahead of flame front prior to normal combustion. This cause a sharp rise of pressure inside the cylinder and cause metal pinging sound known as knock.

What is an example of detonation?

The word ” detonation ” means “to thunder down,” or explode. Examples of chemicals that produce detonations include any high explosives, such as: TNT (trinitrotoluene) nitroglycerine.

What kind of word is detonation?

verb (used with object), det·o·nat·ed, det·o·nat·ing. to cause (something explosive) to explode.

How do you stop detonation?

Detonation Elimination: 9 Ways to Prevent Engine Detonation

  1. #1. Up Your Octane.
  2. #2. Keep Compression Reasonable.
  3. #3. Check Your Timing.
  4. #5. Monitor the Mixture.
  5. #6. Blow out the Carbon.
  6. #7. Examine Your Knock Sensor.
  7. #8. Read Your Spark Plugs.
  8. #9. Consider Your Cooling System.

Why do engines knock?

Knocking occurs when fuel burns unevenly in your engine’s cylinders. When cylinders have the correct balance of air and fuel, fuel will burn in small, regulated pockets instead of all at once. Engine knocking happens when fuel burns unevenly and those shocks go off at the wrong time.

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What does detonation look like on a spark plug?

With the early signs of detonation, the shock-wave will also rattle rings causing the tiny amounts of oil that now gets by rings, to be fused to the white porcelain as tiny black specks, also fused as specks are soot that was clinging to clearance volume surfaces in the relatively “still-air” of the boundary layer.

Is pinging bad for engine?

” Pinging ” is indeed very bad and can permanently damage the internals of the engine. My guess is that’s a combination of off ignition timing, worn ignition components and carbon buildup in the combustion chambers.

What causes engine knock at high rpm?

You may find this problem gets worse as you accelerate. Engine knock is what happens when a portion of the fuel inside the cylinder detonates before the rest of the fuel. Engine knock can also be caused by incorrect ignition timing, an incorrect air/fuel ratio or a malfunctioning knock sensor.

What detonation sounds like?

detonation is refered to as “popcorn” or “bacon” noise, wich it sounds like frying bacon in the pan. It also can be described as somone taking a small ball peen hammer and tapping it on the side of the block.

What causes pre detonation?

Pre – ignition is the ignition of the air- fuel charge while the piston is still compressing the charge. The ignition source can be caused by a cracked spark plug tip, carbon or lead deposits in the combustion chamber, or a burned exhaust valve, anything that can act as a glow plug to ignite the charge prematurely.

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