How does a RDE engine work?
A rotating detonation engine (RDE) is an engine using a form of pressure gain combustion, where one or more detonations continuously travel around an annular channel. Computational simulations and experimental results have shown that the RDE has potential in transport and other applications.
Why are rotating detonation engines more efficient?
This measure of fuel efficiency is calculated by dividing fuel consumption by power output. A rotating detonation engine generates more power, which drives down specific fuel consumption.
Why is detonation more efficient than deflagration?
“Theoretically, the detonation reaction is more efficient, because it produces a lower increase in entropy than the deflagration reaction,” he says. “Furthermore, the chemical reaction in a detonation happens in the high-pressure zone right behind the shock wave.”
What is a pulse wave detonation engine?
The Pulse Detonation Engine (PDE) is an experimental propulsive device that uses supersonic detonation waves as a combustion mechanism. In theory, the PDE design offers numerous advantages over traditional gas turbine engines, including improved efficiency and reduced mechanical complexity.
What is the difference between pre-ignition and detonation?
Detonation causes a very rapid pressure spike near the peak pressure point for a very brief period of time. Pre-ignition causes tremendous pressure that is present for a very long time – possibly the entire compression stroke. Not only is pre-ignition far more damaging, but it’s also much harder to detect.
What is a detonation wave?
A detonation is a supersonic combustion wave that consists of a shock wave driven by energy release from closely coupled chemical reactions. These waves travel at many times the speed of sound, often reaching speeds of Mach 5, as in the case of a hydrogen–air fuel mixture.
What is the difference between a deflagration and an detonation?
3.2 Deflagration and Detonation. Explosives are those substances that have their own supply of oxygen in their molecules. When they are initiated, they may either burn violently (deflagrate) or explode disastrously generating shock waves (detonate).
At what speed does detonation occur?
A detonation occurs when the flame velocity reaches supersonic speeds above 600 m/s and generally in the 2000-2500 m/s range. Peak overpressures can be 20–100 times the initial pressure, with typical values of 20 bar.
What is detonation wave?
What is an oblique detonation wave engine?
Oblique detonation wave engine This engine funnels a mixture of air and fuel at hypersonic speeds (more than five times the speed of sound) toward a ramp, which creates a shock wave. This shock wave heats the mixture and causes it to detonate, ejecting exhaust gasses from the engine.
What is difference between knocking and detonation?
In general, detonation is the cause and knocking is the after effect. Those who deal the terms knocking and detonation as a separate phenomenon, do so by referring auto-ignition theory as knocking and detonation theory as detonation. So, depending on the context it can mean the same thing or different thing.
What is the difference between explosion and detonation?
An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are known as detonations and travel through shock waves.
What is the difference between a deflagration and a detonation?
Is there a difference between detonation and deflagration?
How do detonations and Deflagrations differ?
The maximum pressures developed by deflagrations are often limited by the failure pressure of the surrounding structure. Detonations, on the other hand, tend to shatter, pulverize and splinter nearby materials with fragments propelled away at a very high speeds.
What are the factors affecting detonation?
Factors affecting Detonation or Knocking in SI engine:
- Compression ratio: The pressure and temperature at the end of compression increases with increase in compression ratio.
- Supercharging:
- Increasing inlet temperature:
- Increase in load:
- Advancing the spark:
- Flame travel distance:
- Spark plug location:
- Engine size:
How do you stop detonation?
A plug that’s too hot will retain too much heat, causing detonation. A change to a colder heat range plug is often all that’s needed to shut down unwanted detonation. Be aware, though, that too cold a plug can cause the opposite problem of fouling, which is when a plug fails to fire the air/fuel charge altogether.
What are the three types of explosion?
There are three fundamental types: mechanical, nuclear, and chemical. A mechanical explosive is one that depends on a physical reaction, such as overloading a container with compressed air.
What causes engine detonation?
Detonation occurs when excessive heat and pressure in the combustion chamber causes the air/fuel mixture to ignite on its own. Instead of a typical single flame kernel within the chamber, this creates multiple flames which collide with explosive force.
How is detonation controlled?
Investigations indicate that detonation may be controlled by retarding the rate of combustion by chemicals added to the mixture, which serve to increase its specific heat and prevent excessive temperature, and by reducing the temperature of the walls of the combustion-chamber, so that the temperature of the charge …
Can too much fuel cause detonation?
If the air/fuel mixture is compressed too much, it can detonate. Low coolant or a bad water pump can cause the engine to overheat.