ChannelFlow: InletInSump
Input Parameters:
name Text of up to 10 characters. Blanks are not allowed. This is in order to preserve the tabular printout, which can be read back into the program.
Curb1# This must reference a "Curb" line, in which the inlet is placed.
Curb2#  This must reference a "Curb" line, in which the inlet is placed. This would be the opposing side of the inlet in a sag. If there is no opposing side, and only one curb section and flow is to be referenced, use the same reference as Curb1#.
L Length of the curb opening along the curb.
loc.depr. Local depression at the inlet mouth. It is in addition to any depression of the gutter associated with W and Sw for the curb section. The width of this local depression is assumed to be the same as the gutter, or W dimension given for the curb.
h Height of the inlet opening, measured perpendicular to the angle.
angle Angle of the inlet opening.
Output:
d Depth of flow at the inlet, measured from where the pavement cross-slope (Sx) meets the curb.
di   Depth of flow at the inlet, measured from the inlet lip; (for weir flow: d+a) (for orifice flow; d+h*sin[angle]).
al Local depression, not actually computed output.
a This is the local depression added to the gutter depression associated with W and Sw given for the curb. It is measured from where the line along Sx from the lane would intersect the curb. (12*W*(Sw-Sx)+al)
T Width of spread at the inlet. This will be computed from both referenced curbs, and the wider spread given. The flow is the sum of the curb flows.

The formulas and nomenclature of the Federal Highway Administration's Hydraulic Engineering Circular No. 12 (HEC-12) are used, with further clarification in Hydraulic Engineering Circular No.22 (HEC-22). The referenced formulas are listed below. The default dimensions use a standard VDOT drop inlet.

Qweir = 2.3 (L + 1.8w) d1.5    (for d < h + a) ( 2.3 is 1.25 in metric) (d is measured from the pavement cross slope intersection)

Qorifice = 0.67 h L (2 g do)0.5    (for d > 1.4h) (do is measured to the center of orifice, d(from lip) - (h/2)sin(angle))

(return)