Channel Electrodes and Entry Length

For the channel flow cell and flow rates in Problems 8.1 and 8.2, estimate the distance required for full parabolic flow to be established from the point of entry within the cell. Ckjmment on any implications. 

For a suitably small Reynolds number. Re, to establish laminar flow, the transition from plug flow (on entry) to parabolic flow is established over an entry length of 

In experimental practice, flow rates are usually unlikely to exceed 1 cm s , so that in designing a practical chemical flow cell, an entry length upstream of the working electrode of approximately 0.5 cm should ensure that the appropriate flow profile is established in the vicinity of the channel electrode. 

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