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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]
Propulsive efficiency comparison for various gas turbine engine configurations. In the 1970s, Hamilton Standard described its propfan as "a small diameter, highly loaded multiple bladed variable pitch propulsor having swept blades with thin advanced airfoil sections, integrated with a nacelle contoured to retard the airflow through the blades thereby reducing compressibility losses and ...
Engine efficiency of thermal engines is the relationship between the total energy contained in the fuel, and the amount of energy used to perform useful work. There are two classifications of thermal engines- Internal combustion (gasoline, diesel and gas turbine-Brayton cycle engines) and
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 ...
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 ...
Unintentional detonation when deflagration is desired is a problem in some devices. In Otto cycle, or gasoline engines it is called engine knocking or pinging, and it causes a loss of power. It can also cause excessive heating, and harsh mechanical shock that can result in eventual engine failure. [29]
Aside from giving faster flight speeds turbojets had greater reliability than piston engines, with some models demonstrating dispatch reliability rating in excess of 99.9%. Pre-jet commercial aircraft were designed with as many as four engines in part because of concerns over in-flight failures.