was thinking about how people design the heat risers to have a cyclone action. this rotational heat flow hits the top of the heat radiation barrel in my case the domed top of my 100lb propane tank and is still partially rotating on the downwards flow.. my idea is to weld 3 fins outside the heat riser which will potentially help innfluence a continued downward spiral of exhaust gasses. also at teh bottom of the tank a spiral type ramp going around the heat riser where it buts up agianst the top of the fire box to direct these spiraling exhaust gasses to the exit port ill probably have to draw a picture cause this isnt as easy to read as it is in my head. ...lol
A friend and I where talking about doing the exact same 2 things. Putting 4 fins under the barrel top that would sit on the riser. And shape the exit at the bottom like a cyclone blower cage on ducting fans.
posted 6 years ago
similar at the bottom i was thinking like a less restrictive auger type exit.. i dont believe on the barrell top is the place for the fins though.. im going to place mine about 8 inches down from the top of the riser.
Location: Southern alps, on the French side of the french /italian border 5000ft elevation
posted 6 years ago
Well, the problem with cyclonic action is that it slows gasses. Peter van den Berg's batch rocket has a double spiraling in the heat riser, most of the time. I tried the cyclonic effect in one of my first experiments. With a neutral vane, (for thoses who know) to ease the flow. (otherwise they call it barley or cotton shaker) It was slow to kick into action. But burned extremely clean. I haven't tried to rotate the gasses around the heat riser. I think there's more intresting things to be discovered with venturis than cyclonic imho.
One thing, you want longer radiating time out or the barrel (radiator) make it a bell. Latest consensus 5m² or 50ft² internal surface area for a 6 incher.