On Sat, Nov 19, 2011 at 6:19 PM, Jouni Valkonen <jounivalko...@gmail.com>wrote:
> Joshua wrote: »In the 2-phase literature, this mixture of percolated hot > water and steam is still called low-quality steam.» > > Outside Krivit-inspired Rossi discussion I have never heard this kind of > definition for steam quality. > This doesn't mean very much unless we know what you've read, which clearly doesn't include literature on 2-phase flow. There are lots of articles on it, and I think I gave you a reference before. But a while ago, someone here gave a link to an on-line text book on heat transfer that might help broaden your experience outside Rossi discussion. Go to http://www.wlv.com/products/thermal-management-databooks.html, and click on "Wolverine Heat Transfer Engineering Data Book III", and go to chapter 12. If the link doesn't work, you can go directly to http://www.wlv.com/products/databook/db3/data/db3ch12.pdf. In that chapter you will find all kinds of pictures and plots of different flow regimes for different vapor qualities from zero to 100% quality. Near zero, the flow is mostly liquid with bubbles in it. Vapor quality is simply defined as the ratio of the mass of vapor to the total mass, regardless of how they are mixed. Also wikipaedia does not recognize such definition. > Really? I found this under vapor quality: "The quality of a fluid is the percentage of mass<http://en.wikipedia.org/wiki/Mass> that is vapor <http://en.wikipedia.org/wiki/Vapor>;[1]<http://en.wikipedia.org/wiki/Vapor_quality#cite_note-boles-0> i.e. saturated vapor has a "quality" of 100%, and saturated liquid has a "quality" of 0%. " And also this: "Quality χ can be calculated by dividing the mass of the vapor by the mass of the total mixture: [image: \chi = \frac{m_{vapor}}{m_{total}}] where *m* indicates mass." Nothing specified about the nature of the mixture. Also this in the same article: "The quality of steam can be quantitatively described by *steam quality* (steam dryness), the proportion ofsaturated<http://en.wikipedia.org/wiki/Saturation_(chemistry)> steam <http://en.wikipedia.org/wiki/Steam> in a saturated water/steam mixture.[4] <http://en.wikipedia.org/wiki/Vapor_quality#cite_note-3> i.e., a steam quality of 0 indicates 100% water while a steam quality of 1 (or 100%) indicates 100% steam." Steam quality zero indicates 100% water.
