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What is detonation in chemistry?

What is detonation in chemistry?

A detonation refers to a shock wave in an energetic material that runs at a steady velocity driven by chemical reactions initiated at the shock front [38,39]. Due to damping at edges and surfaces, the detonation state can occur only if the sample is larger than the critical failure diameter [3].

What is burning to detonation?

The Burning to Detonation of Xolid Explosives. A sudden acceleration of the reaction rate behind the shock occurs by a mechan- ism analogous to thermal explosion, and detonation is produced.

What is the process of detonation?

The detonation process is based on repetitive explosions or detonations of oxygen-fuel gas mixtures, rather than the continuous burning of a combustion flame, as in the HVOF process. Oxygen and acetylene are loaded into a long, water-cooled barrel with powder. The mixture is ignited and it explodes.

How do explosions work chemistry?

Chemical explosions can be rapid combustion reactions, where a fuel mixes with air or another oxidizer and becomes ignited. These combustion explosions can involve a fuel in the form of a vapor, dust or mist (e.g., natural gas, propane, finely divided aluminum or magnesium powder, suspended coal dust, etc.)

What is difference between detonation and knocking?

Knocking vs Detonation Knocking is the making sharp sounds due to uneven combustion of fuel in the cylinder of a vehicle engine. Detonation is the process of pre-ignition or auto-ignition of a fuel in an engine’s combustion chamber.

What can cause detonation?

Detonation is generally caused by excessive heat, excessive cylinder pressure, improper ignition timing, inadequate fuel octane or a combination of these. Of the previous, excessive heat is usually the culprit. As an engine is modified to generate more power, additional heat is produced.

What’s the difference between explosion and detonation?

Explosion is a general term for an accelerated release of energy generating extreme temperatures, releasing of gases and expanding volume. Discovered in 1881 by French scientists, detonation is the result of a supersonic wave initiating a secondary explosion.

Is a bomb exploding chemical or physical?

Strictly a physical process, as opposed to chemical or nuclear, e.g., the bursting of a sealed or partially sealed container under internal pressure is often referred to as an explosion.

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. #4. Manage Your Boost.
  5. #5. Monitor the Mixture.
  6. #6. Blow out the Carbon.
  7. #7. Examine Your Knock Sensor.
  8. #8. Read Your Spark Plugs.

How do you stop engine knocking?

How to prevent engine knock?

  1. Retard Ignition Timing. Once the knock sensor receives the signal that knocking has started inside the cylinder, it sends the signal to the ECU.
  2. High Octane Fuel.
  3. Lower Compression Ratio.
  4. Low Cylinder Temperature.

How is detonation diagnosed?

The best way to diagnose detonation in this situation is to install a wide-band oxygen sensor and monitor it during periods of high engine load. A lean condition under full throttle can induce knock at ratios as low as 13:1, and that should tell you not enough fuel is reaching the cylinder.

How is energy released in detonation and combustion?

In both detonation and combustion, energy is released when a complex molecule is broken down into simpler constituent parts; however, as will be explained below, combustion is a much slower process. Low explosives (like black powder) rely on combustion to generate energy.

Which is a characteristic of an explosives detonation?

Explosives are chemical mixtures or compounds that, when subjected to heat, impact, or shock, are capable of undergoing a rapid decomposition that releases heat and gases, which, in turn, expand to form high pressures. Detonation occurs when the rate of chemical decomposition is greater than the speed of sound;

Where does the word detonation come from in physics?

Detonation (from Latin detonare, meaning ‘to thunder down/forth’) is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it.

How does combustion work in a low explosive?

Low explosives (like black powder) rely on combustion to generate energy. Combustion Combustion is produced by the reaction of oxygen and some sort of fuel at high temperatures. As a result, the rate of a combustion reaction is limited both by the amount of fuel present and the amount of oxygen it comes in contact with.