Engines developed by engineer Robert H. Bohanon, in collaboration with NACA in the years 1940 to 1950's.

-They are valveless pulse jets, although partly functioning as ramjet.

"Version without pulsejet"

-The above design does not have the fairing, ducts nor booster that recovers the backfiring thrust from the fresh-air inlet to the chamber.

-In the diagram below if we see a more advanced design with all of the above.

-The length of the lower exhaust tube is what will determine the frequency of explosions in the chamber.

"Advanced Bohanon"