[semo]

I set up a simple case with inlet/outlet and porous jump face in between. It is a simple 5x10x100ft rectangular duct and medium is air. According to Fluent manual, dP across porous jump is:

dp=( mu*v/K+0.5*c*ro*v^2 ) * l

my inputs are:

mu=0.000012 lb/ft.s
ro=0.0765 lb/ft3
vel=5 ft/s
K=1 ft2
C=100 1/ft
l=0.03 ft

using the formula above gives me 2.86 lb/ft2 of dp. Now if I run this Fluent with realizable k-e model I get only 0.079 lb/ft2. I can not figure out why the difference is. Obviously I am doing something wrong.

Thank you for your help...

semo