Here are some more tests comparing different pot sizes on a cat can side burner alcohol stove.
6 pots where used in the tests, 84 mm (heiny), 106.3 mm, 123.5 mm, 137.5 mm, 157 mm, and 204 mm diameter. The stove diameter is 61 mm but being a side burner the flame projects out to have contact with the bottom of larger pots to about 75 mm to 110 mm in diameter which gives an approximate annulus area of 5000 mm^2, this flame contact area is different with smaller pots as the flame was shared by the bottom and the sides, pot/stove ratio is a difficult area to define and in the results I have used the stove diameter in the pot/stove ratio.
Test conditions: 600m (2000ft) elevation, ambient around 20C. Fuel used was standard Australian Methylated Spirits (denatured alcohol) 95% ethanol content. 0.5 liters of tap water was heated from ambient (about 20C) to 95C then g/1 C/0.5l was calculated the result was then standardized by multiplying by 80 to get g/80C/0.5l, which are used in the final results. NOTE: I recorded up to a 5% difference in the amount of fuel used for some pot /stove combinations for these tests, this appears to be a normal amount of variation for stove tests and is why these results are slightly different than some previous results.
Pot dia mm ,fuel used g, pot/stove dia ratio, % of fuel/ compared to 204 pot
84, 21.48, 1.38, 146%
106.3, 19.38, 1.74, 134%
123.5, 18.25, 2.02, 126%
137.5, 17.37, 2.25, 120%
157, 16.23, 2.57, 112%
204, 14.48, 3.34, 100%
Sorry I am unable to lay the table out properly on the site, if any one can help with this I would be greatfull.
NOTE: these results are for this particular cat can stove (pictured below) other stoves will give different results.
CONCLUSION To me there is a clear relationship between pot sizes and flame sizes and efficiency, the greater the pot flame ratio the more efficient the pot/stove system will be.
Future work: I am hoping to do the same tests with a smaller side pressure stove and with some top burner stoves to see if I can find a critical pot/stove ratio.
Pot diameter vs fuel used
performance curve: temperature rise vs time
Stove used in tests
Smallest pot used, notice the flames up the sides