File:Characteristic equations for saturated and superheated steam (1913) (14800380203).jpg

Identifier: characteristiceq00simm (find matches)
Title: Characteristic equations for saturated and superheated steam
Year: 1913 (1910s)
Authors: Simmering, Siebelt Luke
Subjects: Steam Steam, Superheated Theses
Publisher:
Contributing Library: University of Illinois Urbana-Champaign
Digitizing Sponsor: University of Illinois Urbana-Champaign

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
g a too rapid decrease in the totalheat values. Likewise the volumes v, in all probability,were too small. A further correction was found necessary when the spe-cific heat values were determined near the saturation line. 16 They were found to be too low and in order to raise thesevalues it was necessary to add a third tern to the function^T, which then became, = A + BT + ~£ • The values of the constants are, A=.301; B=.00025£; C=7680.7/ith these values when used in conjunction with the preced-ing values given for log M, B, n, and a, there existed asatisfactory agreement with the Knoblauch and Mollier ex-perimental points. When however, a comparison was made with 7 the experiments of Langen at high temperatures, the calcu-lated specific heat curves were found to be too low. After repeated attempts to correct these difficulties,it was decided, that a different form of the characteristicequation was needed. The results of the further investiga-tion are given in the following section.
Text Appearing After Image:
18 Part V.The Revised Equation.To meet the objections raised by Davis and Heck and alsoto embody the conclusions set forth at the beginning ofthis discussion, the characteristic equation has been giv-en the form, pv = BT - p(l+ 3aps);n.In metric units B=47.07; 3a=0.001131; log M=8.654292; n = 4.This equation is essentially the same as the previous equa-tion with the exception of the p term within the paren- i thesis. The combined value of 3ap- being materially greaterthan the single term ap of the former equation. Taking thesquare root of p instead of the first power has a very ben-ifioial effect upon all the values above 400°F. Comparingthe latent heat values of the table on page 25 and thecurves on the preceding page, it is seen very clearly, thatthe Clapeyron - Clausius relation has been satisfied to amarked degree. The specific heat formula becomes, and the total heat formula becomes, iaat=A!E + *Bl2 -;- !Ma±i!p(l + 2ap*)+i0.The values of the constants A, B and C are in metric u

Note About Images