Our experimental program has the following goals.
First, steam filling the envelope of an LTA craft obviously will steadily condense into water and trickle downwards to the low point of the envelope. The first question is: how much parasitic weight is entailed? In other words, at any moment, what mass of water (per square meter) is thus trickling down? This weight is of course a dead load upon the craft.
The second question is: at what rate does the steam condense? That is, first, for a "naked” steam balloon or airship envelope without any insulation jacket, maintained full of steam, how many kilograms of H2O per square meter of the envelope per hour are condensed from steam to water? No attempts ever seem to have been made to quantify this rate of naked condensation; published figures for the loss of heat from steam pipes etc. cannot reliably be applied to the cooling of a very large steam vessel in the outdoors, because of variations in the complex processes of convective cooling with scale. It seems to this writer quite extraordinary that the Steam Airship concept has been repeatedly proposed and discussed, down through the ages, without any effort being made to determine the value of this fundamental naked condensation rate... which, make no mistake, is a high value; but the question is, just how high?
Something we should get out of the way: it is NOT necessary to perform any experiments to determine or verify the lifting power of steam, which is 6.26 newtons per cubic meter in the ISA (International Standard Atmosphere). That is a simple matter of basic physics - see the basic physics page. This lift value doesn't need checking - which cannot be done accurately in practice with small-scale or medium-scale experiments anyway, because of the square-cube law/effect. (Although in fact one of the small-scale experiments does indirectly provide confirmation.)
Furthermore, it is evident that in practice the Steam Balloon and Steam Airship concept really stands or falls upon the question of whether an insulation jacket can actually be manufactured, sufficiently effective in insulating performance to reduce the rate of condensation to an acceptable value, while still sufficiently light to allow the craft to fly. Now the normal methods for testing insulation materials are not very applicable for determining the effectiveness of an insulating jacket material in this special context; see this digression upon the philosophy of insulation. Therefore we cannot rely upon published insulation performance parameters such as "R-values", and we need to derive our own experimental data on the performance of various insulation materials when they are actually applied for insulating the envelope of a Steam Balloon.
On to the small-scale experiments ...
To the mid-scale experiments ...
Back to the experiments page...