Ted Harris

Satamax Antone wrote:There's something else i didn't see at first, your burn tunnel is too long.

Merci Satamax pour tes recommendations...

I don't want to get too technical but as you may have seen on my GrabCad.com page, i happen to be a specialist in CAE/FEA/CFD as i am the maker of ANSYS/Fluent and Icem series of applications.

Everything you said shows a good understanding of some fluid mechanic notions and that is not common among mere mortals !

The intention behind such a narrow space outside the barrel was exactly to cause a short "transition" phase between laminar and turbulent flow to maximize thermal exchange.

Again i don't want to get too technical here but one thing for sure, none of my fancy theories will ever prevail when compared to the experience of people like you. So i will modify the plans to increase the gap outside the barrel. (Thanks for that !)

While making the model, i was wondering the effect of this clearly longer horizontal burning chamber... (It was also intentional but not based on any factual information,.... just intuitive feeling.)

What is the rule of thumb regarding this ? Don't we want to expose the gas to the most heat possible ?

One other thing !... Should my plans say "COB" instead of "Concrete" ?....
Would COB be less "craky" than concrete ?

Thanks for replying...

In, "...flue transition area...",... are you referring to the 'C' or 'D' cross-section ?

The cross-section of the space outside the barrel which bring the gases to the 'D' opening is, as shown in the picture above, equal to 47sqin, which is more that twice the surface area of each of the other cross-sections... I cannot find any 12sqin cross-sections anywhere... can you tell me exactly where you can see that ?

About "laminar flow restriction"... you mean adding surfaces to generate turbulence ?

For your heat riser recommendation not to made it out of metal, i did hesitate between metal and a refractory cylinder... I will change the model to your recommendation. (Metal would get deformed ?)

Thanks and let me know where exactly you spotted 12sqin cross-section.

Satamax Antone wrote:Hi Ted,


Well, the first thing which comes to mind, your barrel to flue transition area is way too small. Even more regarding your barrel side gap which seems in the range of 11/16. Your flue transition hole has a perimeter of 18inches or thereabouts, X 11/16 that's a surface area of about 12 sqin. Too small compared to the 20sqin or thereabouts system size. Plus, the bottom of that transition area hole doesn't do much. And furthermore, you haven't accounted for laminar flow restrictions.

So, make your flue transition about 40 sqin, low and wide. Increase your barrel side gap to 1"1/2 or 2"

And please, don't use metal for the heat riser.



J.D. Ray, i think it's solidworks, as stated in the first post

J.D. Ray wrote:I can't say anything one way or the other about your dimensions, but wow, those are beautiful renderings. What did you use to model? And to render?

Cheers to you.

JD

This model and all detailled pdf plans are available to download on https://grabcad.com/ted.harris-1/projects

Everything was made in SolidWorks 2011. Renderings also in Solidworks.

Thanks for the comments

Here's some additional pictures to help out...

Greetings !

I just finished a set of blueprints for a mass rocket stove i might build this spring... (Everything is published here)

I was wondering if someone would validate the dimensions of my main cross-sections ?... (To get a proper draft)

I attached some of the main pictures to this post... the complete SolidWorks/STEP CAD files are available on my GrabCad.com account.

Thanks !