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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]
In a multi-engine aircraft, if one engine fails, it can be feathered to reduce drag so that the aircraft can continue flying using the other engine(s). In a single-engine aircraft, if the engine fails, feathering the propeller will reduce drag and increase glide distance, providing the pilot with more options for the location of a forced landing.
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 ...
A corollary of this is that, particularly in air breathing engines, it is more energy efficient to accelerate a large amount of air by a small amount, than it is to accelerate a small amount of air by a large amount, even though the thrust is the same. This is why turbofan engines are more efficient than simple jet engines at subsonic speeds.
A pulse detonation engine (PDE) is a type of propulsion system that uses detonation waves to combust the fuel and oxidizer mixture. [ 1 ] [ 2 ] The engine is pulsed because the mixture must be renewed in the combustion chamber between each detonation wave and the next.
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 ...
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.