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The engine used gaseous methane and oxygen as propellants, generating an average thrust of 518 N and delivering 290 seconds of specific impulse. Rotating combustion also created a torque of 0.26 N·m, so a S-shaped pulse detonation engine was used to reduce the spin of the stage. [27] [28]
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. [3]
The Humphrey cycle is the thermodynamic cycle occurring detonation engines such as rotating detonation engines, the pulse detonation engines, and pulse compression detonation systems. It may be considered to be a modification of the Brayton cycle in which the constant-pressure heat addition process of the Brayton cycle is replaced by a constant ...
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 ...
Engine Origin Designer Vehicle Status Use Propellant Power cycle Specific impulse (s) [a] Thrust (N) [a] Chamber pressure (bar) Mass (kg) Thrust: weight ratio [b] Oxidiser: fuel ratio
The theoretical maximum efficiency of a heat engine, the Carnot efficiency, depends only on its operating temperatures. Mathematically, this is because in reversible processes, the cold reservoir would gain the same amount of entropy as that lost by the hot reservoir (i.e., d S c = − d S h {\displaystyle dS_{\mathrm {c} }=-dS_{\mathrm {h ...
The pulse detonation engine (PDE) marks a new approach towards non-continuous jet engines and promises higher fuel efficiency compared to turbofan jet engines, at least at very high speeds. Pratt & Whitney and General Electric now have active PDE research programs. Most PDE research programs use pulsejet engines for testing ideas early in the ...
Higher compression ratios can make gasoline (petrol) engines subject to engine knocking (also known as "detonation", "pre-ignition", or "pinging") if lower octane-rated fuel is used. [5] This can reduce efficiency or damage the engine if knock sensors are not present to modify the ignition timing.