Well, I'm not sure that what you describe above is the proper use of the term "controls", but I understand your point. To me an experimental control is a standard to which you compare different experimental conditions. I guess you might use something like a vacuum cleaner as a control. Obviously there will be differences between smokers, and I agree with your point. Personally I just find it an interesting problem, so I spent a little time thinking about how it should be formulated.random wrote:I'm using the term "controls" in its basic science meaning. The fact that every individual smoker causes a different level of airflow through the system, and that airflow is irregular, makes any definitive comparison very difficult. Certaily you could hook a pipe up to a vacuum cleaner or something to get a consistent airflow, but then you'd be designing the pipe for a vacuum cleaner not a real smoker. We're working with generalities here. Certainly an understanding of the thermodynamic principles at play are useful and can help us make improvements, but they will almost certainly not provide <b><i>The Answer</i></b>
Heat issues and wall thickness
Random:
If one has two embers, one small and the other larger, burning at your "minimum temperature" and one were to add a greater volume of oxygen to the smaller ember then it would burn at a higher temperature. This would produce more heat per volume and possibly more total heat. The heat of a burning ember is not restricted to the minimum temperature.
A black smith needs high temperatures to work iron. Burning coal or wood in a fireplace will not creat high enough temperatures to do this. These temperatures can be reached by burning coal or wood and adding more oxygen to it. Thus, not only producing more heat but also higher temperatures.
Again, you continue to fix your position with the assumption of "minimum temperature". Obviously, heat and temperature are not the same thing. Temperature is the concentration or intensity of a volume of heat. Heat is amount of movement of particles. Hence, a swimming pool of 40 degree water has more heat then a cup of boiling water despite the pool's lower temperature.An ember burning at the minimum temperature required for combustion of the blend in question will have the same temperature regardless of its size
If one has two embers, one small and the other larger, burning at your "minimum temperature" and one were to add a greater volume of oxygen to the smaller ember then it would burn at a higher temperature. This would produce more heat per volume and possibly more total heat. The heat of a burning ember is not restricted to the minimum temperature.
A black smith needs high temperatures to work iron. Burning coal or wood in a fireplace will not creat high enough temperatures to do this. These temperatures can be reached by burning coal or wood and adding more oxygen to it. Thus, not only producing more heat but also higher temperatures.
Actually, Random, I do consider most of those things you mention. I haven't added on the bit about a mortise/tenon gap, but I could without too much trouble. I had thought about it, but kinda decided against it. I suppose if one were interested in checking out one's existing pipes this would be a good feature to have, presuming that one has pipes with a mortise tenon gap.Wrong answers guaranteed. You are not considering chamber configuration, drafthole shape, gaps in mortise/tenon area, any narrowing or widening at the bit/outlet. This is the kind of "oh that's easy" thinking that has held progress back for a long time, now stop it Nick you are smarter than that!
It was a fun project to work on, and thats mainly why I did it. I just thought I'd offer it to anyone interested. No biggie either way.
If you are truly looking for a full three-dimensional model, you're NOT going to be doing this in Excel. My guess is you will be looking for a finite element package like FIDAP or something similar. Something capable of using numerical methods to solve pretty complex partial differential equations. If you're interested in what I think the full three-dimensional equation would look like I can email you that little lunchtime project I took up last week - it's in there. I also went through an analytical solution for a simplified one-dimensional model (although I never had the chance to go back through it to look for errors - even the 1-D version gets a little messy).random wrote:As a programmer, I'd be interested in learning how you describe the curvature of the tobacco chamber and the shape of the draft hole and bit outlet such that Excel can cope with them and the user doesn't go bazonko trying to enter data.
Best way to handle things like the curvature of the bowl and the flare at the end of the stem would be to let r be a function of z, where r is the radius of the tobacco chamber or the radius of the draft hole and z is the axial direction.
I didn't think about the curvature at the bottom of the chamber. I do have it set to differentiate between round and tapered bowls. Additionally, the equations I used were written for round pipes, so I think the shape of the draugh passage was taken into account. Tapers and such can be accounted for too.
All in all, you're probably right. The figures it provides aren't totally accurate. It was fun doing though, and might provide some insight to how things work. If one is looking for more precision, there is a whole subfield of fluid dynamics that deals with computational things, and tons of software for it. Unfortunately, the software is 'spensive.
All in all, you're probably right. The figures it provides aren't totally accurate. It was fun doing though, and might provide some insight to how things work. If one is looking for more precision, there is a whole subfield of fluid dynamics that deals with computational things, and tons of software for it. Unfortunately, the software is 'spensive.