The Ergun equation for calculating clean bed headloss ( Table 8-2 ) has been proposed fo...

The Ergun equation for calculating clean bed headloss ( Table 8-2 ) has been proposed for use in cases where larger media and higher filtration rates are used such as deep bed monomedium filters. The first term in the Ergun equation accounts for viscous forces. The second term accounts for inertial forces. Calculate the ratio of the inertial term to the total headloss estimate for various filtration rates using a spreadsheet you have written. Assume the following values:

Identify the filtration rate at which the inertial term accounts for half of the clean bed headloss. See Trussell and Chang (1999) for more on k_v and k_i.