Hello dato.
I am elated that you'd like to emulate any of my work! I wracked my brain and if that saves someone from having to do so, that's wonderful!
Here is the link for tripwires, secondary air flow and those swoops and turbulators. Matt, our lovely host, is also involved over on the donkeyboards so I don't mind posting to something elsewhere... I'll share a little of my process and ideas with you but DEFINITELY read this thread. If you don't know about our friends over at Dragon Burners and of the remarkable Peter van de Burg, you have some great goodies to explore!
Here's the link.
http://donkey32.proboards.com/thread/355?page=1 I discovered the tripwire issue too late, and flipping the board would have put the tripwire near the heat riser and not the feed tube, but a great idea! The tripwire keeps the unburnt gases from (theoretically) just flowing across the top of the burn tunnel. Peters discovery is that it separates the flow, pushing it down and towards the back corners along the outside edges. There it then hits the swoops (that's what I call them, I don't know if anyone has invented or given them a name) that scoop them up in the other direction, collecting them and then the turbulator at this apex tumbles the burning gases more, right up into the heat riser.
Now to mention something we play with a bit here, Matt at the helm, these little differences might make a difference, but potentially pretty small ones. The more little tweaks that work together the greater the efficiency, thus my desire to tinker with them. In the local vernacular of where I live, "It don't hurt!" Most importantly we must remember to relax (and have a homebrew if it suits you) and press on, work and share our victories and foibles. A great deal has happened in the past couple years, and I haven't even known about this stuff a year yet!
Before I forget, I made a 6" system, I already had some pipe so went with it. The 8" are that much hotter, but I like the daintiness of the six. On that note I almost bought the demure 4" dragon burner core, but that's just too small after some experimenting, and for the price of the core I have created my whole system. Don't get me wrong, the dragon cores are absolutely incredible, but ultimately, I really wanted to build my own, damned independent New Englander!...
Now, when I build another core, and I will, I think the swoops on the back should meet in the middle of the back of the burn tunnel, essentially making the entire back wall NOT flat, and going as high as the feedtube, height/ceiling of the burn tunnel. The turbulator works in the opposite way, the flat top where the swoops stop. Great image of half the core on the above mentioned thread. I was limited by the random chunk of 4x4 I tucked into the back. Next time I'll just put in a bigger chunk, it won't be 4x4!
This'll sound a bit esoteric until you read the thread. True that the thread can get pretty, uh, nerdy (and I mean that lovingly) but to read it as the thoughts evolve is remarkable, but I'm a nerd! I plan on playing around with the "Peter plate" once things are further along, I have some final dimensions. I plan on covering the whole thing with tile eventually so might tinker with a couple different secondary air intakes.
It's worth noting that there are tons and tons of RMH with simple 90 degree angles that building with rectangles (bricks) is a byproduct of that work very well. Since I wasn't using bricks, I wanted to play around!
It is also worth noting that the Peter plate, tripwire, swoops and turbulator all work in concert together. The ideal symphony a healthy roar bereft of smoke replete with maximum extraction of heat! Whew...
Hope this fans your fire, as it were! Keep it rockety~p