Role of fluid properties in gas transfer

Temperature dependence of stream aeration coefficients and the effect of water turbulence: A critical review

“…Although Elmore and West (1961) did not find significant differences in q with change in turbulence, both earlier studies (Kishinevsky, 1954;Kishinevsky and Serebryansky, 1956), and later studies (Dobbins, 1964;Metzger and Dobbins, 1967;Metzger, 1968) contradicted this finding both theoretically and experimentally. It is worth noting that Elmore and West (1961) two experiments were run within a narrow range of turbulence: K L ¼ 0.02 cm min À1 to 0.05 < K L < 0.12 cm min À1 (the latter depending on the size of the vortex that may have increased the water surface up to a very unlikely maximum of 2.4 times).…”

“…It soon appeared that while the original papers presented succinctly the theory, they did not provide all the necessary details to repeat the calculations and did not compute the temperature correction coefficient q for a wide range of temperature and stream turbulence. Moreover, on closer inspection, while rL 3 term (see below) should be constant under a given temperature (Dobbins, 1964;Metzger and Dobbins, 1967), this was not true from the values reported in the tables of the Metzger papers, hence the q curves provided in Fig. 2 of Metzger (1968) might have been incorrect.…”

Reaeration in open-channel flow

“…Using Kolmogoroff s limit for the size of the energy-dissipating eddies, he obtained Dobbins (1964b), they obtained where c2 and c4 are the same constants as in the Dobbins theory and ci, c3, and cs are new constants, and where c5 is independent of the flow dynamics. For distilled water, Metzger and Dobbins (1967) found -=1.…”

“…That this method predicts kL values for natural streams as well as it does is therefore a little surprising. The Dobbins (1964b) and Metzger and Dobbins (1967) methods are more rational and more sophisticated, and they require the evaluation of two experimental coefficients. Equation 60 used by Dobbins (1964b) to predict c4 was obtained from a plot of field data that contains considerable scatter.…”

“…The larger values in general have been used (Isaacs and Gaudy, 1968;Metzger and Dobbins, 1967;Kozinski and King, 1966;Dobbins, 1964b;O'Connor and Dobbins, 1958). Himmelblau (1964) also believed that the smaller values at 25°C were probably incorrect, and Baird and Davidson (1962) believed that the larger values obtained with the wetted sphere procedure were more accurate than the values obtained with the annular jet.…”