On Thu, Jul 21, 2011 at 5:22 AM, Damon Craig <[email protected]> wrote:
> Look, guys. If no one is pursuing the "really wet steam" theory anymore the > steam wetness issue is pretty much moot. Sorry if I didn't realize that. > What gives you that idea? To my mind, really wet steam is still the most likely explanation for what is observed in Rossi's demos. My earlier reply to Lomax was devoted to making this point. By the time it reaches the end of the hose, I suspect there is probably some separation of phases; that is from entrained droplets to some flowing liquid. Lewan collects about half of the input liquid in his bucket. The rest of the liquid probably comes out as fine droplets (mist). > > > Originally, you may recall, numbers caste about were as high as 97% liquid > by mass. This is dense enough a chunk of oak would float in it. > Please. 97% liquid by mass is still only 2% liquid by volume. That means the density would be .02*1g/cc + .98*(1/1700)g/cc = .02 g/cc, about 50 times less dense than water. This sort of wet steam (3% quality) is entirely plausible and is studied extensively in the literature. > Even 10% mass exceeds our usual experiences of steam wetness in my > estimate. > And what is your estimate based on? Probably not on forcing steam and water through a conduit using a pump. The mist produced by an ultrasonic mist humidifier contains only liquid (at first). There is no vapor produced at all. The fine droplets evaporate after they are suspended in the air. I was interested in buoyancy, not entrainment in a moving fluid. > Obviously the droplets are not buoyed by the steam. They are entrained. > > > Steam wetness is still an interesting question, in and off itself, but not > that interesting here, unless there is anyone still arguing it. It seems it > would take a huge amount of energy to randomly break surface tension so > often to generate buoyant droplets, such that the argument would defeat > itself. > What is huge? It takes far more energy to vaporize it. In fact in calorimetric measurements of steam quality, no consideration of surface tension is made. It is negligible. > > > The densest suspensions one might likely find are at the base of a Niagara > Falls and I don't think this would float a cork. > That mist, like the mist from a cool humidifier is of course mixed with air, but what you do see is that the droplets are in fact suspended in the air. And when it's windy, the mist is carried along with the wind. Entrainment!
