Pulse detonation engine is an engine where the low pressure combustion is converted into high pressure detonation wave by changing the cross sectional area of the detonation tube. The cross section area will be converging type at the object placed inside the tube which holds the combustible mixture and provides a rapid combustion where the detonation wave is followed by the combustion flame. Two distinct types of flame fronts occur within a pulse detonation engine called as deflagration and detonation. A deflagration wave is a subsonic flame front that propagates by heat transfer. A detonation wave is a supersonic flame front that consists of a shock wave coupled with a trailing reaction zone. The principle differences between a deflagration and detonation wave are the wave speeds and pressure difference across the wave. A detonation wave is a supersonic combustion wave consisting of a shock wave coupled with a reaction zone. The conditions behind an ideal detonation wave are dictated by the Chapman-Jouguet (CJ) condition that the flow behind the wave is sonic in a reference frame moving with the detonation velocity. The pulse detonation engine has a length of a half wavelength of the resonance frequency.
Last date updated on January, 2021