An Ex plumber in the UK has been playing with these for a long time, amongst other stuff. He has turned his experimental and wacky stuff into a source of income by YouTube. See
for how simple it is to make a "no moving parts" engine. He made a larger one, which he fixed to his truck, loud enough to be heard across the English channel (22 miles!) and went to the south coast to Fart at the French. If a turbo charger from a vehicle is added the efficiency can be increased but so is the cost. Enjoy.
Rans6...........................