Preliminary study of a pulse normal detonation wave engine

A novel pulse normal detonation wave engine (PNDWE) is investigated from the viewpoint of entropy generation associated with combustion, whereas entropy production is detrimental to the efficiency of propulsion systems. To evaluate the relative advantages of different combustion modes for propulsion, the engine is studied in a given flight situation for a fixed amount of energy release during the combustion. Preliminary analysis suggests that compared with conventional subsonic combustion ramjet and Scramjet, PNDWE has superiority in theory, even though steady normal detonation engine is much inferior to the deflagration-based engine, for a given flight condition and a given amount of heat release. The principle of selecting the Mach number before unsteady detonation wave is also given. The superior range of flight Mach number for PNDWE is concluded to be about 3 to 7. Additionally, the influence of the exit boundary on the pulse normal detonation wave is discussed.