There are two versions of the pulse-detonation wave engines. The first one is the flap scramjet. That engine is the modified version of the flap jet engine. During WW2, Germans used that engine in a V-1 cruise missile. The flap scramjet is the scramjet engine that has a flap system. When the speed is too slow for ignition of the scramjet engine the system injects an oxygen fuel mixture into that engine. And that engine uses regular rocket mode until the aircraft is about Mach-6-7 when operators open the air intakes. Then the system can start to use air from the atmosphere. That thing makes the system very powerful and multi-use. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX The pistol shrimp has given an idea for PDWS systems. The idea of the Pulse-Detonation Wave System ( PDWS) is coming from the pistol shrimp. That small shrimp can create a low-pressure bubble in water. The temperature in that bubble rises to 5000 kelvins. And that thing causes a very strong sound. If an