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Prediction of batch heat transfer coefficients for pseudoplastic fluids ...

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72<br />

(3-77<br />

Substituting these terms in equations 3-75 ru~d<br />

3-73 ~nd<br />

placing the Prandtl number in the nu..merator, as <strong>for</strong> Ne1oJtonian<br />

(3-78<br />

or<br />

C YRe" -;;;;;; -; A?~ (~- ( ~ nv<br />

K"J1I Dei<br />

( / -2~ I- cZ ) / K) J? /[J ) C d<br />

(3-79<br />

Equation 3-79 then characterizes <strong>heat</strong> <strong>transfer</strong> to pmver law<br />

<strong>fluids</strong> being agitated by geometrically similar marine<br />

propellers. This characterization is based on a model which<br />

is believed to represent the flo1.J patterns fairly accurately.<br />

If the impeller geometry changes; that is, if the vertical<br />

"VJill increase<br />

and thus a higher Nusselt number will result. Equation<br />

3-79 may be expanded to correct <strong>for</strong> geometrically unsimilar<br />

impellers by adding a sixth di!l1ensionless term, WalDa' where<br />

\-1 a is the impeller 1rddth ..<br />

AI. - c NJ~:;: f~/" iI.(f)i~V CjNjci e<br />

AI U - Re /Vp-1. K'w (Ii (;;- -1V (3-80<br />

at<br />

Other geometry effects could be taken into account by adding<br />

more dimensionless groups such as found in the dimensional<br />

analysis <strong>for</strong> Newtonian <strong>fluids</strong> as presented in equation 2-35.<br />

4i

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