Mass transport circular tube

Flow in circular tubes is of interest to many corrosion engineers. A large number of correlations exist for mass transport due to turbulent flow in a smooth straight pipe (4,9). The flow is transitionally turbulent at Re 2 X 103 and is fully turbulent at Re 105 (4). The most frequently used expression for turbulent conditions at a straight tube wall is that given by Chilton and Colburn using the analogy from heat transfer (13) ... 

With such a flat plate, the boundaiy layer will increase in thickness in-dcfinitely if slowly (Fig. 1.10(c))l On the other hand if the flow is in a restricted channel (e.g. a circular-tube or a paraltel-plate cell) the boundary layers at the two walls must merge at some point and beyond, a steady-state situation or fully developed laminar flow will result (Fig. Ltl). Fundamental mass transport studies in electrolytic cells are usually carried out in cells with an entry length without electrodes so that the boundary-layer thickness is uniform over the current-carrying surface. 

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