Coincidentally François H. Reynst discovered that burning alcohol in a container with a hole produced a pulsating combustion

-He came to the conclusion that after the first expulsion, ambient air re-entered the container forming a whirlpool and it burned again.

“Reynst, explaining drawing”

-The fuel was introduced into a small chamber where it was mixed with air and after combustion it entered the front blind chamber. By adding a nozzle the frequency could be increased.

“Reynst's experiment”

-We would see this principle in the S. Roe pulse jets.