Does anyone know

In trying to increase the heat output of my little Rock-it Im considering rounding the sharp corner of the floor of my burn chamber where it meets the vertical wall leading into the riser. Sort of like porting and polishing to increase flow. Im going to try it by rounding the corner a little with furnace cement. I can always grind it out if it doesnt help. Think Ill round the inner corner too

I think you will mess it up if you do that.

We want sharp corners in a rocket stove, because we want turbulent flow. You start filling in sharp corners and rounding edges, and the flow is going to become more laminar. If it does that, then unburned gases will travel further up the chimney where they may cool to the point that they don't burn at all, just put out more creosote and smoke. And with laminar flow, it won't roar, so you won't have a "rocket" stove.

It actually worked very well. Increased the heat from less than my 23,000 btu kerosene heater to its hard to stand next to it lol. Stay tuned this dumb polack still has a few more tricks up his sleeve. I can hot rod anything. When I rounded the floor of the burn chamber with cement I purposely left some swirl ridges to create turbulence. This thing is roasting hot on like 3 1x2 pieces of wood. Im in the middle of tweaking it a bit more. Will report back

Joe Sylwestrzak wrote: When I rounded the floor of the burn chamber with cement I purposely left some swirl ridges to create turbulence.

Nie zły! Pan wie o turbulencji.

John Elliott wrote:
We want sharp corners in a rocket stove, because we want turbulent flow. You start filling in sharp corners and rounding edges, and the flow is going to become more laminar.

shouldn't the burn tunnel be smooth, and the inside of the heat riser have corners? Or is it the other way around. Please let me know ASAP, since I can still correct my mistakes, as I'm still in the building stage with nothing cobbed in yet.

Thanks in Advance!

That's quite interesting what you have done there Joe. I haven't built one yet, but I was thinking along those lines also. I wonder if the oleo effect (swirling water down a drain) works with flue gasses. If there is a tendency for flue gasses to swirl up the flue in a certain direction (and pitch) then that could be encouraged by incorporating "swirl bumps". Whether this would help with heat output or burn efficiency is another question I guess. I wonder if anyone has done this sort of research.