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Fuel and oxidizer are injected into the channel, normally through small holes or slits. A detonation is initiated in the fuel/oxidizer mixture by some form of igniter. After the engine is started, the detonations are self-sustaining. One detonation ignites the fuel/oxidizer mixture, which releases the energy necessary to sustain the detonation.
Above this speed, given sufficient initial flight velocity, a ramjet is self-sustaining. Unless the vehicle drag is extremely high, the engine/airframe combination tends to accelerate to higher and higher flight speeds, substantially increasing the air intake temperature. As this could damage the engine and/or airframe integrity, the fuel ...
A pulsejet engine (or pulse jet) is a type of jet engine in which combustion occurs in pulses.A pulsejet engine can be made with few [1] or no moving parts, [2] [3] [4] and is capable of running statically (that is, it does not need to have air forced into its inlet, typically by forward motion).
The Fickett–Jacobs (FJ) cycle is based on Chapman–Jouguet (CJ) theory, an approximation for the detonation wave's velocity during a detonation. [ 1 ] [ 2 ] This cycle is researched for rotating detonation engines (RDE), considered to be more efficient than the classical combustion engines that are based on the Brayton or Humphrey cycles .
On 26 July 2021 (UTC), Japan's space agency JAXA successfully tested a pulse detonation rocket engine in space on a S-520 sounding rocket flight. [9] The upper stage of the rocket used a rotating detonation engine (RDE) as the main engine and a S-shaped pulse detonating engine was used to de-spin the stage after the main engine burn. PDE ...
As the piston approaches the TDC the combustible mixture is self-ignited due to the compression of it. Then, the deflagration to the detonation transition occurs in the detonation tube 9. The output of detonation products from the tube 9 happens in a short period of time, when the piston is near the TDC. Then, the process is repeated.
In pulse detonation engines, direct detonation of the combustible mixture can be relatively straightforward, but require more energy than when detonation is preceded by deflagration. The deflagration to detonation transition (DDT) must however occur within the length of the detonation tube, which can be solved by providing the Shchelkin spiral ...
Starting of a gas turbine engine requires rotation of the compressor to a speed that provides sufficient pressurised air to the combustion chambers. The starting system has to overcome inertia of the compressor and friction loads, the system remains in operation after combustion starts and is disengaged once the engine has reached self-idling ...