1. In Eq. (12), K ^-^(u^/fap/dx is defined as the permeability and is determined using the empirical relation K = 03D2/[c^l-^)2] where C, is set equal to 147 based on the work of Kuwahara et al.5. The value of C2is set to either 1.75 as suggested by Kuwahara et al.5or to 2.3 based on the classical result of Ergun26. Calculations presented inthe results shows that the total drag from a collection of spheres shows the overall drag isnot sensitive tothevalue of C2. In the bluff body limit, the clutter is treated as a collection of spheres for which the total number of spheres in the filtering volume can be related to porosity and ratio of clutter to filtering size using the relation: Ns=61-0jD/A//;r- InEq. (13), CDis the coefficient of drag of each sphere given by the following empirical relation.=J24(l+Re/3/6)/ReDforReD<1000 "1 0.424
2. Nakayama etal. 1999 PedrasetaL2001 Present Result
3. Nayayamaetal.,1999 Pedrasetal., 2001 Present Results