Using AutoCAD 2012 with SSA, FHWA HEC-22 Generic inlet.
When I put in a sweeper inlet with a curb opening length less than the grate length, the amount of flow captured is greater than just grate. Does this mean that the curb opening length is just the extra distance.
Ex. 2' grate with 4' curb opening (2' above the grate, 2' upstream)
Flow of grate = 2cfs
Flow with 1' grate =2.1cfs
Flow with 2' grate = 2.5 cfs
Flow with 4' grate = 3 cfs.
I thought HEC-22 was to ignore any curb opening placed over the grate, but this does not appear to be the case. Or am I missing something.
Thanks,
Dan.
