Turbulator Revisited

[pinhead]

After watching the twin-screw pattern in Peter Van Den Berg's batch box, Donkey's heart-shaped turbulator again seems to show some serious merit.

www.youtube.com/watch?v=GyR36Frbse4

Strangely enough, when I first built my Peterberg Batch Box, I noticed that the stovepipe which I used to form the heat riser had expanded and created a very similar shape, though it went for about half of the height of the riser. The twin-screw pattern was extremely pronounced, even more so than in the above video. The rocket roar was much more pronounced as well.

Luckily I'm in the process of building a batch rocket that I may be able to use for some testing. Unfortunately I don't have any test equipment so the "results" will be little more than pictures, video, and sniff tests.

That is, if I can scrounge up the materials I need and can make the thing hold together -- i may have bitten off more than I can chew on this particular project.

Has anyone else experimented with this type of riser in a PVDB Batch Box? Or in a J-tube rocket? It seems that this shape could be used as a secondary air injector as well...

[4seasons]

Interesting concept. I wonder if the twin cyclone of the Turbulator is better than the single cyclone created by a j-tube kick tail. I have been working under the idea that a single cyclone would speed up the system and create a more efficient burn but could more turbulence be the key instead? I get why you want turbulence in the burn tunnel but I was thinking that you want speed out of the heat riser. Am I wrong and you need to maximize the total system turbulence for the best performance?

[Donkey]

Good question.
Someone either needs to build both models side-by-side or one stove with the ability to quick-change and do the experiment.

It seems to me that with a batch-box, much of the burn happens inside the heat riser, in which case, the "rams horn" double turbulence pattern makes sense.
In the J-tube, especially with p-channel and tripwire installed, the flame is pretty well done by the time it reaches the riser.
Don't know.. Do the experiment and let us know how it goes!