Effective leading edge

While the axial position of multistage impellers to their diffusers is not critical, they should line up reasonably well. Impellers are not extremely sensitive to leading-edge dings and minor damage, but anything, such as erosion on the exit tips, that tends to decrease the effective diameter of the impeller is more serious. Front shroud clearance on open impellers should be maintained close to the design values to minimize capacity loss. 

The steady-state iso-concentration lines, deduced from the numerical treatment are plotted in Fig. 5-2. The effect of the x diffusion term (d2c/dx2) of Eq. (5-2) is important at the leading edge of the microelectrode when this term is dropped, all the isoconcentration lines start from this same point. 

It appears that the concentration profiles of the two leading edges coincide reasonably well and one may assume that the memory effect on the concentration distribution is lost over one or few active sites. This last result hence justifies the procedure of considering one site located in the wake of a macroelectrode. 

Some effects of matrix interferences that cause elevated PQLs cannot be overcome even with the leading edge preparation and analysis techniques. 

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